Transformation of glycerol into value-added che micals via electro-oxidation using the green electricity is considered as a sustainable and promising process.Whereas,the synthesis of specific C3 products such as glyce...Transformation of glycerol into value-added che micals via electro-oxidation using the green electricity is considered as a sustainable and promising process.Whereas,the synthesis of specific C3 products such as glyceric acid(GLA)from electro-oxidation of glycerol still suffers from poor catalytic performance.Here,we used a two-step deposition strategy to prepare Au-CeO_(2)/CNT catalyst for highly efficient electrosynthesis of GLA from glycerol oxidation under alkaline conditions.Upon treating 0.5 mol/L glycerol at 1.12 V(vs.RHE)for 12 h in 1.0 mol/L KOH solution,the glycerol conversion and GLA selectivity over Au-CeO_(2)/CNT achieve 99.7%and 50.0%,respectively.The glycerol conversion doubles when an optimal amount of CeO_(2)is introduced to the Au/CNT catalyst,Au-CeO_(2)/CNT provides numerous active sites at ternary junctions of Au-CeO_(2)-CNT,which effectively suppress the adsorption of GLA on the surface of Au nanoparticles and prevent the nanoparticles from serious agglomeration,thereby facilitate the glycerol-to-GLA conversion with considerable cyclability.This study provides valuable insight into the rational design of high-performance catalysts for alcohol electro-oxidation.展开更多
Photoelectrochemistry is a promising method for the direct conversion of sunlight into valuable chemicals by combining the functions of solar panels and electrolyzers in one technology.In most studies,semiconductor/ca...Photoelectrochemistry is a promising method for the direct conversion of sunlight into valuable chemicals by combining the functions of solar panels and electrolyzers in one technology.In most studies,semiconductor/catalyst photoelectrode assemblies are used to achieve reasonable efficiencies.At the same time,unlike in dark electrochemical processes,the role of the catalyst is not straightforward in photoelectrochemistry,where the onset potential of the redox process should be mostly determined by the flatband potential of the semiconductor.In addition,the energy of holes(i.e.,the surface potential)is independent of the applied bias;it is defined by the valence band(VB)position.In this study,we compared PdAu,Au,and Ni on Si photoanodes in the photoelectrochemical(PEC)oxidation of glycerol at record high current densities(>180 mA cm^(‒2)),coupled to H_(2) evolution at the cathode.We successfully decreased the energy requirement(i.e.,the cell voltage)of the paired conversion of glycerol and water by 0.7 V by exchanging the widely studied Ni catalyst with PdAu.The catalyst choice also dictates the product distribution,resulting mainly in C3 products on PdAu,glycolate(C2 product)on Au,and formate(C1 product)on Ni,without complete mineralization of glycerol(CO_(2) formation)that is difficult to rule out in dark electrochemical processes(as demonstrated by comparative measurements).Finally,we achieved a bias‐free(standalone)operation with PdAu/Si and Au/Si photoanodes by combining the PEC oxidation of glycerol with oxygen reduction reaction(ORR).展开更多
Hydrogen production from electrolytic water is an important sustainable technology to realize renewable energy conversion and carbon neutrality.However,it is limited by the high overpotential of oxygen evolution react...Hydrogen production from electrolytic water is an important sustainable technology to realize renewable energy conversion and carbon neutrality.However,it is limited by the high overpotential of oxygen evolution reaction(OER)at the anode.To reduce the operating voltage of electrolyzer,herein thermodynamically favorable glycerol oxidation reaction(GOR)is proposed to replace the OER.Moreover,vertical Ni O flakes and NiMoNH nanopillars are developed to boost the reaction kinetics of anodic GOR and cathodic hydrogen evolution,respectively.Meanwhile,excluding the explosion risk of mixed H_2/O_(2),a cheap organic membrane is used to replace the expensive anion exchange membrane in the electrolyzer.Impressively,the electrolyzer delivers a remarkable reduction of operation voltage by 280 mV,and exhibits good long-term stability.This work provides a new paradigm of hydrogen production with low cost and good feasibility.展开更多
The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The c...The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The continuously operated radial flow cell consisted of a borehole electrode positioned 50μm above an internal reflection element enabling operando FTIR spectroscopy.It is identified as a suitable tool for facile and reproducible screening of electrocatalysts under well-defined conditions,additionally providing access to the selectivities in complex reaction networks such as glycerol oxidation.The fast product identification by ATR-IR spectroscopy was validated by the more time-consuming quantitative HPLC analysis of the pumped electrolyte.High degrees of glycerol conversion were achieved under the applied laminar flow conditions using 0.1 M glycerol and 1 M KOH in water and a flow rate of 5μL min^(–1).Conversion and selectivity were found to depend on the catalyst loading,which determined the catalyst layer thickness and roughness.The highest loading of 210μg cm^(–2)resulted in 73%conversion and a higher formate selectivity of almost 80%,which is ascribed to longer residence times in rougher films favoring readsorption and C–C bond scission.The lowest loading of 13μg cm^(–2)was sufficient to reach 63%conversion,a lower formate selectivity of 60%,and,correspondingly,higher selectivities of C_(2)species such as glycolate amounting to 8%.Thus,only low catalyst loadings resulting in very thin films in the fewμm thickness range are suitable for reliable catalyst screening.展开更多
One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐r...One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐ray diffraction,X‐ray photoelectron spectroscopy,and high‐resolution transmission electron microscopy revealed that the alloy phases of PtPb and PtxPb were favorable for pyruvic acid production from glycerol oxidation,whereas the Pb3(CO3)2(OH)2and surface Pb0species inhibited the glycerol conversion.The loading of Pb and the catalyst preparation method(including impregnation and deposition precipitation)affected the formation of different metal species.Pyruvic acid was obtained at a yield of18.4%on a5.0wt%Pb‐5.0wt%Pt/AC catalyst prepared by co‐deposition precipitation method and500°C argon treatment.展开更多
Rhodium nanoparticle-loaded carbon black (Rh/CB) was prepared by a wet method, and its activity and durability for glycerol oxidation reaction (GOR) in alkaline medium were compared with Pt, Pd and Au nanoparticle-loa...Rhodium nanoparticle-loaded carbon black (Rh/CB) was prepared by a wet method, and its activity and durability for glycerol oxidation reaction (GOR) in alkaline medium were compared with Pt, Pd and Au nanoparticle-loaded CB (Pt/CB, Pd/CB and Au/CB). In the cyclic voltammogram of the Rh/CB electrode, the redox waves due to hydrogen adsorption/desorption and the surface OH monolayer formation/reduction were observed at more negative potentials than the Pt/CB and Pd/CB electrodes. The onset and peak potentials of the GOR current densities for the Rh/CB electrode were ca. –0.55 and –0.30 V vs. Hg/HgO, respectively, which were 0.10 and 0.20 V more negative than the Pt/CB electrode whose GOR activity was the best, indicating that Rh was a fascinating metal for reducing the overpotential for GOR. In the electrostatic electrolysis with the Rh/CB and Pt/CB electrodes, the decrease in the GOR current density in the former with time was suppressed compared to that in the latter, suggesting that the tolerance to poisoning for the Rh/CB electrode was superior to that for the Pt/CB electrode.展开更多
To improve the activity for glycerol oxidation reaction (GOR) of Pt, PtAg (mole ratio of Pt/Ag = 3 and 1) alloy nanoparticle-loaded carbon black (Pt/CB, PtAg(3:1)/CB, PtAg(1:1)/CB) catalysts were prepared by a wet met...To improve the activity for glycerol oxidation reaction (GOR) of Pt, PtAg (mole ratio of Pt/Ag = 3 and 1) alloy nanoparticle-loaded carbon black (Pt/CB, PtAg(3:1)/CB, PtAg(1:1)/CB) catalysts were prepared by a wet method. The resultant catalysts, moreover, were heat-treated in a N2 atmosphere at 200°C. The alloying of Pt with Ag for each PtAg/CB was confirmed by X-ray diffractometry and electron dispersive X-ray spectrometry. The heat-treatment did not change the crystal structure of the PtAg alloys and increased their particle size. X-ray photoelectron spectroscopy exhibited that stabilizers were completely removed from the PtAg alloy surface, and the Pt4f and Ag3d doublets due to metallic Pt and Ag, respectively, shifted to lower binding energies, supporting the alloying of Pt with Ag. Both PtAg/CB electrodes had two oxidation waves of glycerol irrespective of heat-treatment, which was different from the Pt/CB electrode. The onset potential of the first oxidation wave was -0.60 V, which was 0.20 V less positive than that for the Pt/CB electrode, indicating the alloying of Pt with Ag greatly improved the GOR activity of Pt. The heat-treated PtAg(3:1)/ CB electrode improved the GOR current density of the second oxidation peak. In the potentiostatic electrolysis at -0.1 and 0 V for both PtAg/CB electrodes, the ratio of oxidation current density at 60 min to that at 5 min (j<sub>60</sub>/j<sub>5</sub>), an indicator of the catalyst deterioration, at 0 V was higher than that at -0.1 V, because the adsorbed oxidation intermediates were greatly consumed at the larger overpotential. The heat-treatment of the PtAg(3:1)/CB electrode increased the j60</sub>/j5</sub> value at -0.1 V but decreased that at 0 V. This could be attributed to the formation of high-order oxidation intermediates which might have stronger poisoning effect.展开更多
Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxi...Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxidation reaction(GOR);however,glycerol inevitably dissociates and converts to carbon dioxide on the Pd surface,which results in its low total Faradaic efficiency(FE)for high-value-added products.Herein,a series of Pd/C and Pd10Bix/C catalysts were synthesized to investigate the GOR pathway.The Pd10Bi3/C catalyst with optimal Bi content achieved an excellent GOR mass activity of 7.5±0.2 A mgPd−1 and an outstanding total FE of 90%±3%,which are much higher than those values on Pd/C(1.2±0.2 A mgPd−1 for mass activity and 63%±4%for total FE).Combined results of in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy and density functional theory calculations show that Bi suppresses the dissociation of glycerol through the“shielding effect”of Bi to the adjacent Pd sites,which weakens the adsorption strength of GOR intermediates on those sites.This work provides a new insight into the GOR mechanism and puts forward a valid strategy for the rational design of catalysts to enable the transformation of glycerol into high-value-added products.展开更多
Aldehydes are valuable intermediates with widespread industrial applications,and their traditional synthesis relies on chemical oxidation that is often hazardous and environmentally unfriendly.Electrochemical oxidatio...Aldehydes are valuable intermediates with widespread industrial applications,and their traditional synthesis relies on chemical oxidation that is often hazardous and environmentally unfriendly.Electrochemical oxidation offers a more sustainable and milder alternative;however,it faces challenges such as aldehyde overoxidation and susceptibility to base-catalyzed Cannizzaro disproportionation.Electrochemical glycerol oxidation to glyceraldehyde is a representative example,which typically requires precious metal-based electrocatalysts but still suffers from low selectivity and activity.Here,we report a metal-free oxidation strategy mediated by 2,2,6,6-tetramethylpiperidine-1-oxyl.By systematically investigating the redox thermodynamics and kinetics of TEMPO across a broad pH range,we construct a Pourbaix diagram and elucidate the relative kinetics of each reaction step.These insights allow us to explain the anomalously high apparent Faradaic efficiency(~200%)observed under acidic conditions,and identify neutral media as the optimal environment for selective glyceraldehyde production.Under optimized conditions,our system achieves a glyceraldehyde Faradaic efficiency exceeding 93%and a partial current density of 23.3 mA cm^(-2)at 0.57 V—more than doubling the performance of the best reported precious metal-based systems.Furthermore,the versatility of this strategy extends to the selective oxidation of other primary alcohols to their corresponding aldehydes with near-unity selectivity.展开更多
The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;d...The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;denoted as Ni NCs)were prepared for the electrocatalytic glycerol oxidation toward formic acid,in which Ni_(6)-PET-50CV afforded the most excellent electrocatalytic performance with a high formic acid selectivity of 93% and a high glycerol conversion of 86%.This was attributed to the lowest charge transfer impedance and the most rapid reaction kinetics.Combined electrochemical measurements and X-ray absorption fine structure measurements revealed that the structures of Ni NCs remained intact after CV scanning pretreatment and electrocatalysis via forming the Ni–O bond.Additionally,the kinetic studies and in-situ Fourier transformed infrared suggested a sequential oxidation mechanism,in which the main reaction steps of glycerol→glyceraldehyde→glyceric acid were very rapid to produce a high selectivity of formic acid even though the low glycerol conversion.This work presents an opportunity to study Ni NCs for the efficient electrocatalytic oxidation of biomass-derived polyhydroxyl platform molecules to produce value-added carboxylic acids.展开更多
The rational design of highly efficient bifunctional electrocatalysts,capable of robust operation across both oxidative and reductive electrochemical environments,is paramount for next-generation energy conversion and...The rational design of highly efficient bifunctional electrocatalysts,capable of robust operation across both oxidative and reductive electrochemical environments,is paramount for next-generation energy conversion and environmental remediation technologies.Crucially,a unified copper-based catalyst platform,engineered with precisely tailored oxidation states uniquely suited for disparate reaction conditions,offers a paradigm for substantially simplifying electrolyzer architectures without compromising electrocatalytic efficacy at either electrode.Herein,we address this challenge by synthesizing copper oxide nanorods(CuO NRs)possessing systematically modulated reduction extents.Electrochemical investigations demonstrate that partially reduced CuO NRs(r-CuO NRs)exhibit exceptional activity and selectivity for cathodic nitrate reduction to ammonia(FE_(NH3 % )= 96.8%),whereas pristine CuO NRs display superior performance for anodic glycerol oxidation to formate(FE_(Formate%)=93%).These findings underscore the strategic imperative of precisely controlling copper oxidation state manipulation in advancing sustainable chemical synthesis and environmental remediation strategies.展开更多
Glycerol(electrochemical) oxidation reaction(GOR) producing organic small molecule acid and coupling with hydrogen evolution reaction is a critical aspect of ensuring balanced glycerol capacity and promoting hydrogen ...Glycerol(electrochemical) oxidation reaction(GOR) producing organic small molecule acid and coupling with hydrogen evolution reaction is a critical aspect of ensuring balanced glycerol capacity and promoting hydrogen generation on a large scale. However, the development of highly efficient and selective non-noble metal-based GOR electrocatalysts is still a key problem. Here, an S-doped CuO nanorod array catalyst(S-CuO/CF) constructed by sulfur leaching and oxidative remodeling is used to drive GOR at low potentials: It requires potentials of only 1.23 and 1.33 V versus RHE to provide currents of 100 and 500 mA cm^(-2), respectively. Moreover, it shows satisfactory comprehensive performance(at 100 mA cm^(-2), V_(cell) = 1.37 V) when assembled as the anode in asymmetric coupled electrolytic cell. Furthermore, we propose a detailed cycle reaction pathway(in alkaline environment) of S-doped CuO surface promoting GOR to produce formic acid and glycolic acid. Among them, the C–C bond breaking and lattice oxygen deintercalation steps frequently involved in the reaction pathway are the key factors to determine the catalytic performance and product selectivity. This research provides valuable guidance for the development of transition metal-based electrocatalysts for GOR and valuable insights into the glycerol oxidation cycle reaction pathway.展开更多
A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt%and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at at...A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt%and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure,45℃ and pH =11.The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy（SEM-EDX） and transmission electron microscopy（TEM）.The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy（XPS）.Glycerol conversion obtained with the monometallic Pd catalyst was 19%,which was increased to 100%with the addition of Pb.The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone（DIHA） and the selectivity to DIHA reached 59%,58%,34%and 25%for PdPb0.25,PdPb0.50,PdPb1.00 and PdPbl.60 catalysts,respectively.展开更多
The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was ...The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.展开更多
Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation an...Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation and subsequent calcination.The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid(GLA)up to 90%with 59%conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions.The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation.Notably,it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca^(2+) sites on HAP-derived catalysts.In this catalytic process,the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group,while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA.Additionally,this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding a-hydroxycarboxylic acids selectively.Isotope labeling experiment using H_(2)^(18)O confirmed that H_(2)O not only acted as solvent but also was involved in the catalytic cycles.On the basis of the results,a possible reaction mechanism has been proposed.The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals.展开更多
The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development ...The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development of efficient bifunctional electrocatalysts.Herein,we put forward a high-efficiency coelectrolysis system by coupling the nitrite reduction reaction(NO_(2)RR)and the glycerol oxidation reaction(GOR)over a novel heterogeneous β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl catalyst.Theβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl shows excellent bifunctional performance with high Faradaic efficiencies of formate(90.1%)and NH_(3)(91.9%)at cell voltage of 1.5 V,high yield rate of formate(89.6 mg h^(-1)cm^(-2))and NH_(3)(36.07 mg h^(-1)cm^(-2))at cell voltage of 1.9 V,and superior stability in an anion exchange membrane co-electrolyzer.The in-situ Raman result confirms the unique Co/Cu-based bimetallic synergistic sites of β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl towards superior GOR performance,while the operando Fourier transform infrared spectroscopy demonstrates the improved protonation kinetics of key intermediates and optimized water dissociation ability ofβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl for high NO_(2)RR activity.Our work illuminates alternative avenues to exploit the innovative and energy-saving technology for the co-production of high-added chemicals.展开更多
The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au-Pt, Au-...The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au-Pt, Au- Pd and Pt-Pd catalysts on TiO2 were examined under base-free conditions. Pt exhibited a superior activity relative to Pd, and Au-Pd and Pt-Pd while Au was essentially inactive. The presence of Au on the Au-Pt/TiO2 catalysts led to their higher activities （normalized per Pt atom） in a wide range of Au/Pt atomic ratios （i.e. 1/3-7/1 ）, and the one with the Au/Pt ratio of 3/1 exhibited the highest activity. Such promoting effect is ascribed to the increased electron density on Pt via the electron transfer from Au to Pt, as characterized by the temperature-programmed desorption of CO and infra-red spectroscopy for CO adsorption. Meanwhile, the presence of Au on Au-Pt/TiO2, most like due to the observed electron transfer, changed the product selectivity, and facilitated the oxidation of the secondary hydroxyl groups in glycerol, leading to the favorable formation of dihydroxyacetone over glyceraldehyde and glyceric acid that were derived from the oxidation of the primary hydroxyl groups. The synergetic effect between Au and Pt demonstrates the feasibility in the efficient oxidation of glycerol to the targeted products, for example, by rational tuning of the electronic properties of metal catalysts.展开更多
Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and p...Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.展开更多
Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale...Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale deployment of the technology.Coupling energy-efficient electrooxidation of biomassderived glycerol and cathodic hydrogen evolution reaction provides a promising strategy for improving the techno-economics of the water electrolysis technology.Herein,by dispersing transition metal elements with weak d-p coupling strength into the MnO_(2)lattice,the fine tuning of the bioctahedral d-p orbital in MnO_(2)is successfully realized,which greatly accelerates the hydrogen transfer in glycerol oxidation.In-situ Raman results confirmed that Ni–MnO_(2)could spontaneously activate glycerol molecules and drive hydrogen transfer to lattice oxygen sites,leading to the occurrence of successive phase transitions(α-MnO_(2)→Mn_(3)O_(4)→MnOOH).Density functional theory(DFT)calculations revealed that the incorporation of Ni broadened the d-orbital and regulated the distribution of p-orbitals near the oxygen Fermi level in the lattice,resulting in a relatively high empty orbital state to facilitate the hydrogen transfer process.The optimal Ni–MnO_(2)delivered a low potential of 1.16 V vs.RHE to reach 10 mA cm^(-2),a high FE of 99.7%for formate,and superior durability over 80 h.This work provides new insights into balancing the adsorption and activation of biomass molecules while casting a universal strategy for developing efficient biomass oxidation electrocatalysts.展开更多
Energy-saving glycerol electrolysis with lower potential than water spitting endows a promising way for the concurrent production of value-added formate and high-purity hydrogen. However, there is still lack of effici...Energy-saving glycerol electrolysis with lower potential than water spitting endows a promising way for the concurrent production of value-added formate and high-purity hydrogen. However, there is still lack of efficient electrocatalysts at both anode and cathode for glycerol electrolysis. Herein, we report the activation of Ni site in NiV layered double hydroxide(LDH) by electrochemical and N_(2)/H_(2) plasma regulations for boosting the activity of glycerol oxidation reaction(GOR) and hydrogen evolution reaction(HER), respectively. Specifically, boosted GOR performance with a low overpotential(1.23 V at 10 mA·cm^(-2)) and a high Faradic efficiency(94%) is demonstrated by electrochemically regulated NiV LDH(ENiV LDH) with elevated valence state of Ni site. In situ Raman spectrum reveals the generation of Ni(Ⅲ) species by electrochemical regulation, and the highly active Ni(Ⅲ)can be regenerated with the process of electrochemical oxidation. Additionally, the possible reaction pathway is speculated based on the in situ Fourier transform infrared spectroscopy(FTIR) and high-performance liquid chromatography results. The plasma-regulated NiV LDH(PNiV LDH) with lower valence state of Ni site exhibits outstanding HER activity, displaying a low overpotential of 45 m V to deliver 10 mA·cm^(-2).When employing E-NiV LDH and P-NiV LDH as anode and cathode electrocatalyst, respectively, the assembled electrolyzer merely needs 1.25 V to achieve 10 m A·cm^(-2) for simultaneous production of formate and hydrogen, demonstrating remarkable 320 mV of lower potential than water electrolysis.展开更多
基金Project supported by the National Natural Science Foundation of China(22161033,21875125)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2023ZD11)+1 种基金the 111 Project(D20033)the"Grassland Talent"Program and"Grassland Talent"Innovation Team of Inner Mongolia。
文摘Transformation of glycerol into value-added che micals via electro-oxidation using the green electricity is considered as a sustainable and promising process.Whereas,the synthesis of specific C3 products such as glyceric acid(GLA)from electro-oxidation of glycerol still suffers from poor catalytic performance.Here,we used a two-step deposition strategy to prepare Au-CeO_(2)/CNT catalyst for highly efficient electrosynthesis of GLA from glycerol oxidation under alkaline conditions.Upon treating 0.5 mol/L glycerol at 1.12 V(vs.RHE)for 12 h in 1.0 mol/L KOH solution,the glycerol conversion and GLA selectivity over Au-CeO_(2)/CNT achieve 99.7%and 50.0%,respectively.The glycerol conversion doubles when an optimal amount of CeO_(2)is introduced to the Au/CNT catalyst,Au-CeO_(2)/CNT provides numerous active sites at ternary junctions of Au-CeO_(2)-CNT,which effectively suppress the adsorption of GLA on the surface of Au nanoparticles and prevent the nanoparticles from serious agglomeration,thereby facilitate the glycerol-to-GLA conversion with considerable cyclability.This study provides valuable insight into the rational design of high-performance catalysts for alcohol electro-oxidation.
基金funding under the European Union's Horizon Europe research and innovation program from the European Research Council(ERC,Grant Agreement No.101043617)(C.J.).Project No.RRF‐2.3.1‐21‐2022‐00009titled National Laboratory for Renewable Energy,was implemented with the support provided by the Recovery and Resilience Facility of the European Union within the framework of the Program Széchenyi Plan Plus(C.J.)support from MICIU/AEI/10.13039/501100011033/(PID2020-116093RB−C41 and PID2023‐152771OB‐I00).European Innovation Council(EIC)(101071010).
文摘Photoelectrochemistry is a promising method for the direct conversion of sunlight into valuable chemicals by combining the functions of solar panels and electrolyzers in one technology.In most studies,semiconductor/catalyst photoelectrode assemblies are used to achieve reasonable efficiencies.At the same time,unlike in dark electrochemical processes,the role of the catalyst is not straightforward in photoelectrochemistry,where the onset potential of the redox process should be mostly determined by the flatband potential of the semiconductor.In addition,the energy of holes(i.e.,the surface potential)is independent of the applied bias;it is defined by the valence band(VB)position.In this study,we compared PdAu,Au,and Ni on Si photoanodes in the photoelectrochemical(PEC)oxidation of glycerol at record high current densities(>180 mA cm^(‒2)),coupled to H_(2) evolution at the cathode.We successfully decreased the energy requirement(i.e.,the cell voltage)of the paired conversion of glycerol and water by 0.7 V by exchanging the widely studied Ni catalyst with PdAu.The catalyst choice also dictates the product distribution,resulting mainly in C3 products on PdAu,glycolate(C2 product)on Au,and formate(C1 product)on Ni,without complete mineralization of glycerol(CO_(2) formation)that is difficult to rule out in dark electrochemical processes(as demonstrated by comparative measurements).Finally,we achieved a bias‐free(standalone)operation with PdAu/Si and Au/Si photoanodes by combining the PEC oxidation of glycerol with oxygen reduction reaction(ORR).
基金the financial support from National Natural Science Foundation of China(92163117,52072389,52172058,51972006)。
文摘Hydrogen production from electrolytic water is an important sustainable technology to realize renewable energy conversion and carbon neutrality.However,it is limited by the high overpotential of oxygen evolution reaction(OER)at the anode.To reduce the operating voltage of electrolyzer,herein thermodynamically favorable glycerol oxidation reaction(GOR)is proposed to replace the OER.Moreover,vertical Ni O flakes and NiMoNH nanopillars are developed to boost the reaction kinetics of anodic GOR and cathodic hydrogen evolution,respectively.Meanwhile,excluding the explosion risk of mixed H_2/O_(2),a cheap organic membrane is used to replace the expensive anion exchange membrane in the electrolyzer.Impressively,the electrolyzer delivers a remarkable reduction of operation voltage by 280 mV,and exhibits good long-term stability.This work provides a new paradigm of hydrogen production with low cost and good feasibility.
文摘The influence of the drop-casted nickel boride catalyst loading on glassy carbon electrodes was investigated in a spectroelectrochemical ATR-FTIR thin-film flow cell applied in alkaline glycerol electrooxidation.The continuously operated radial flow cell consisted of a borehole electrode positioned 50μm above an internal reflection element enabling operando FTIR spectroscopy.It is identified as a suitable tool for facile and reproducible screening of electrocatalysts under well-defined conditions,additionally providing access to the selectivities in complex reaction networks such as glycerol oxidation.The fast product identification by ATR-IR spectroscopy was validated by the more time-consuming quantitative HPLC analysis of the pumped electrolyte.High degrees of glycerol conversion were achieved under the applied laminar flow conditions using 0.1 M glycerol and 1 M KOH in water and a flow rate of 5μL min^(–1).Conversion and selectivity were found to depend on the catalyst loading,which determined the catalyst layer thickness and roughness.The highest loading of 210μg cm^(–2)resulted in 73%conversion and a higher formate selectivity of almost 80%,which is ascribed to longer residence times in rougher films favoring readsorption and C–C bond scission.The lowest loading of 13μg cm^(–2)was sufficient to reach 63%conversion,a lower formate selectivity of 60%,and,correspondingly,higher selectivities of C_(2)species such as glycolate amounting to 8%.Thus,only low catalyst loadings resulting in very thin films in the fewμm thickness range are suitable for reliable catalyst screening.
基金supported by the National Natural Science Foundation of China(21176236)~~
文摘One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐ray diffraction,X‐ray photoelectron spectroscopy,and high‐resolution transmission electron microscopy revealed that the alloy phases of PtPb and PtxPb were favorable for pyruvic acid production from glycerol oxidation,whereas the Pb3(CO3)2(OH)2and surface Pb0species inhibited the glycerol conversion.The loading of Pb and the catalyst preparation method(including impregnation and deposition precipitation)affected the formation of different metal species.Pyruvic acid was obtained at a yield of18.4%on a5.0wt%Pb‐5.0wt%Pt/AC catalyst prepared by co‐deposition precipitation method and500°C argon treatment.
文摘Rhodium nanoparticle-loaded carbon black (Rh/CB) was prepared by a wet method, and its activity and durability for glycerol oxidation reaction (GOR) in alkaline medium were compared with Pt, Pd and Au nanoparticle-loaded CB (Pt/CB, Pd/CB and Au/CB). In the cyclic voltammogram of the Rh/CB electrode, the redox waves due to hydrogen adsorption/desorption and the surface OH monolayer formation/reduction were observed at more negative potentials than the Pt/CB and Pd/CB electrodes. The onset and peak potentials of the GOR current densities for the Rh/CB electrode were ca. –0.55 and –0.30 V vs. Hg/HgO, respectively, which were 0.10 and 0.20 V more negative than the Pt/CB electrode whose GOR activity was the best, indicating that Rh was a fascinating metal for reducing the overpotential for GOR. In the electrostatic electrolysis with the Rh/CB and Pt/CB electrodes, the decrease in the GOR current density in the former with time was suppressed compared to that in the latter, suggesting that the tolerance to poisoning for the Rh/CB electrode was superior to that for the Pt/CB electrode.
文摘To improve the activity for glycerol oxidation reaction (GOR) of Pt, PtAg (mole ratio of Pt/Ag = 3 and 1) alloy nanoparticle-loaded carbon black (Pt/CB, PtAg(3:1)/CB, PtAg(1:1)/CB) catalysts were prepared by a wet method. The resultant catalysts, moreover, were heat-treated in a N2 atmosphere at 200°C. The alloying of Pt with Ag for each PtAg/CB was confirmed by X-ray diffractometry and electron dispersive X-ray spectrometry. The heat-treatment did not change the crystal structure of the PtAg alloys and increased their particle size. X-ray photoelectron spectroscopy exhibited that stabilizers were completely removed from the PtAg alloy surface, and the Pt4f and Ag3d doublets due to metallic Pt and Ag, respectively, shifted to lower binding energies, supporting the alloying of Pt with Ag. Both PtAg/CB electrodes had two oxidation waves of glycerol irrespective of heat-treatment, which was different from the Pt/CB electrode. The onset potential of the first oxidation wave was -0.60 V, which was 0.20 V less positive than that for the Pt/CB electrode, indicating the alloying of Pt with Ag greatly improved the GOR activity of Pt. The heat-treated PtAg(3:1)/ CB electrode improved the GOR current density of the second oxidation peak. In the potentiostatic electrolysis at -0.1 and 0 V for both PtAg/CB electrodes, the ratio of oxidation current density at 60 min to that at 5 min (j<sub>60</sub>/j<sub>5</sub>), an indicator of the catalyst deterioration, at 0 V was higher than that at -0.1 V, because the adsorbed oxidation intermediates were greatly consumed at the larger overpotential. The heat-treatment of the PtAg(3:1)/CB electrode increased the j60</sub>/j5</sub> value at -0.1 V but decreased that at 0 V. This could be attributed to the formation of high-order oxidation intermediates which might have stronger poisoning effect.
基金supported by the National Natural Science Foundation of China(Grant number 22172112)and the Fundamental Research Funds for the Central Universities.
文摘Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry.Pd is one of the few active catalysts for alkaline glycerol oxidation reaction(GOR);however,glycerol inevitably dissociates and converts to carbon dioxide on the Pd surface,which results in its low total Faradaic efficiency(FE)for high-value-added products.Herein,a series of Pd/C and Pd10Bix/C catalysts were synthesized to investigate the GOR pathway.The Pd10Bi3/C catalyst with optimal Bi content achieved an excellent GOR mass activity of 7.5±0.2 A mgPd−1 and an outstanding total FE of 90%±3%,which are much higher than those values on Pd/C(1.2±0.2 A mgPd−1 for mass activity and 63%±4%for total FE).Combined results of in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy and density functional theory calculations show that Bi suppresses the dissociation of glycerol through the“shielding effect”of Bi to the adjacent Pd sites,which weakens the adsorption strength of GOR intermediates on those sites.This work provides a new insight into the GOR mechanism and puts forward a valid strategy for the rational design of catalysts to enable the transformation of glycerol into high-value-added products.
文摘Aldehydes are valuable intermediates with widespread industrial applications,and their traditional synthesis relies on chemical oxidation that is often hazardous and environmentally unfriendly.Electrochemical oxidation offers a more sustainable and milder alternative;however,it faces challenges such as aldehyde overoxidation and susceptibility to base-catalyzed Cannizzaro disproportionation.Electrochemical glycerol oxidation to glyceraldehyde is a representative example,which typically requires precious metal-based electrocatalysts but still suffers from low selectivity and activity.Here,we report a metal-free oxidation strategy mediated by 2,2,6,6-tetramethylpiperidine-1-oxyl.By systematically investigating the redox thermodynamics and kinetics of TEMPO across a broad pH range,we construct a Pourbaix diagram and elucidate the relative kinetics of each reaction step.These insights allow us to explain the anomalously high apparent Faradaic efficiency(~200%)observed under acidic conditions,and identify neutral media as the optimal environment for selective glyceraldehyde production.Under optimized conditions,our system achieves a glyceraldehyde Faradaic efficiency exceeding 93%and a partial current density of 23.3 mA cm^(-2)at 0.57 V—more than doubling the performance of the best reported precious metal-based systems.Furthermore,the versatility of this strategy extends to the selective oxidation of other primary alcohols to their corresponding aldehydes with near-unity selectivity.
文摘The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;denoted as Ni NCs)were prepared for the electrocatalytic glycerol oxidation toward formic acid,in which Ni_(6)-PET-50CV afforded the most excellent electrocatalytic performance with a high formic acid selectivity of 93% and a high glycerol conversion of 86%.This was attributed to the lowest charge transfer impedance and the most rapid reaction kinetics.Combined electrochemical measurements and X-ray absorption fine structure measurements revealed that the structures of Ni NCs remained intact after CV scanning pretreatment and electrocatalysis via forming the Ni–O bond.Additionally,the kinetic studies and in-situ Fourier transformed infrared suggested a sequential oxidation mechanism,in which the main reaction steps of glycerol→glyceraldehyde→glyceric acid were very rapid to produce a high selectivity of formic acid even though the low glycerol conversion.This work presents an opportunity to study Ni NCs for the efficient electrocatalytic oxidation of biomass-derived polyhydroxyl platform molecules to produce value-added carboxylic acids.
基金supported by National Key Research and Development Program of China(No.2024YFE0211200)China Postdoctoral Science Foundation(No.2025M770156)+4 种基金Shaanxi Province Postdoctoral Science Foundation(No.2024BSHSDZZ080)Science and Technology Innovation Team of Shaanxi Province(Nos.2023-CX-TD-27 and 2022TD-35)Fundamental Research Funds for the Central Universities(Nos.GK202506037 and GK202505036)the Technology Innovation Leading Program of Shaanxi in Chinathe Technology Innovation Teams in Shaanxi Province in China.
文摘The rational design of highly efficient bifunctional electrocatalysts,capable of robust operation across both oxidative and reductive electrochemical environments,is paramount for next-generation energy conversion and environmental remediation technologies.Crucially,a unified copper-based catalyst platform,engineered with precisely tailored oxidation states uniquely suited for disparate reaction conditions,offers a paradigm for substantially simplifying electrolyzer architectures without compromising electrocatalytic efficacy at either electrode.Herein,we address this challenge by synthesizing copper oxide nanorods(CuO NRs)possessing systematically modulated reduction extents.Electrochemical investigations demonstrate that partially reduced CuO NRs(r-CuO NRs)exhibit exceptional activity and selectivity for cathodic nitrate reduction to ammonia(FE_(NH3 % )= 96.8%),whereas pristine CuO NRs display superior performance for anodic glycerol oxidation to formate(FE_(Formate%)=93%).These findings underscore the strategic imperative of precisely controlling copper oxidation state manipulation in advancing sustainable chemical synthesis and environmental remediation strategies.
基金financially supported by National Natural Science Foundation of China (52174283 and 52274308)。
文摘Glycerol(electrochemical) oxidation reaction(GOR) producing organic small molecule acid and coupling with hydrogen evolution reaction is a critical aspect of ensuring balanced glycerol capacity and promoting hydrogen generation on a large scale. However, the development of highly efficient and selective non-noble metal-based GOR electrocatalysts is still a key problem. Here, an S-doped CuO nanorod array catalyst(S-CuO/CF) constructed by sulfur leaching and oxidative remodeling is used to drive GOR at low potentials: It requires potentials of only 1.23 and 1.33 V versus RHE to provide currents of 100 and 500 mA cm^(-2), respectively. Moreover, it shows satisfactory comprehensive performance(at 100 mA cm^(-2), V_(cell) = 1.37 V) when assembled as the anode in asymmetric coupled electrolytic cell. Furthermore, we propose a detailed cycle reaction pathway(in alkaline environment) of S-doped CuO surface promoting GOR to produce formic acid and glycolic acid. Among them, the C–C bond breaking and lattice oxygen deintercalation steps frequently involved in the reaction pathway are the key factors to determine the catalytic performance and product selectivity. This research provides valuable guidance for the development of transition metal-based electrocatalysts for GOR and valuable insights into the glycerol oxidation cycle reaction pathway.
基金supported by CONICET(PIP 0276)UNLP(Projects X 700)+1 种基金UNNOBA(SIB 2924/14)Ministry of Education and Sports(Call "Jorge Sabato" Project 44-144-415),Argentina
文摘A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt%and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure,45℃ and pH =11.The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy（SEM-EDX） and transmission electron microscopy（TEM）.The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy（XPS）.Glycerol conversion obtained with the monometallic Pd catalyst was 19%,which was increased to 100%with the addition of Pb.The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone（DIHA） and the selectivity to DIHA reached 59%,58%,34%and 25%for PdPb0.25,PdPb0.50,PdPb1.00 and PdPbl.60 catalysts,respectively.
基金Chulalongkorn University Dutsadi Phiphat Scholarshipthe Ratchadapisek Sompoch Endowment Fund(Sci-Super Ⅱ GF_58_08_23_01)the Thailand Research Fund(IRG5780001) for financial support
文摘The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.
基金support from the National Natural Science Foundation of China(21773061,21978095)Innovation Program of Shanghai Municipal Education Commission(15ZZ031)the Fundamental Research Funds for the Central Universities。
文摘Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation and subsequent calcination.The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid(GLA)up to 90%with 59%conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions.The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation.Notably,it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca^(2+) sites on HAP-derived catalysts.In this catalytic process,the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group,while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA.Additionally,this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding a-hydroxycarboxylic acids selectively.Isotope labeling experiment using H_(2)^(18)O confirmed that H_(2)O not only acted as solvent but also was involved in the catalytic cycles.On the basis of the results,a possible reaction mechanism has been proposed.The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals.
基金financially supported by the National Natural Science Foundation of China(22205205)the Science Foundation of Zhejiang Sci-Tech University(ZSTU)under Grant No.21062337-Y。
文摘The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development of efficient bifunctional electrocatalysts.Herein,we put forward a high-efficiency coelectrolysis system by coupling the nitrite reduction reaction(NO_(2)RR)and the glycerol oxidation reaction(GOR)over a novel heterogeneous β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl catalyst.Theβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl shows excellent bifunctional performance with high Faradaic efficiencies of formate(90.1%)and NH_(3)(91.9%)at cell voltage of 1.5 V,high yield rate of formate(89.6 mg h^(-1)cm^(-2))and NH_(3)(36.07 mg h^(-1)cm^(-2))at cell voltage of 1.9 V,and superior stability in an anion exchange membrane co-electrolyzer.The in-situ Raman result confirms the unique Co/Cu-based bimetallic synergistic sites of β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl towards superior GOR performance,while the operando Fourier transform infrared spectroscopy demonstrates the improved protonation kinetics of key intermediates and optimized water dissociation ability ofβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl for high NO_(2)RR activity.Our work illuminates alternative avenues to exploit the innovative and energy-saving technology for the co-production of high-added chemicals.
基金supported by the National Basic Research Program of China (2011CB201400 and 2011CB808700)the National Natural Science Foundation of China (21373019, 21173008 and 21433001)
文摘The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au-Pt, Au- Pd and Pt-Pd catalysts on TiO2 were examined under base-free conditions. Pt exhibited a superior activity relative to Pd, and Au-Pd and Pt-Pd while Au was essentially inactive. The presence of Au on the Au-Pt/TiO2 catalysts led to their higher activities （normalized per Pt atom） in a wide range of Au/Pt atomic ratios （i.e. 1/3-7/1 ）, and the one with the Au/Pt ratio of 3/1 exhibited the highest activity. Such promoting effect is ascribed to the increased electron density on Pt via the electron transfer from Au to Pt, as characterized by the temperature-programmed desorption of CO and infra-red spectroscopy for CO adsorption. Meanwhile, the presence of Au on Au-Pt/TiO2, most like due to the observed electron transfer, changed the product selectivity, and facilitated the oxidation of the secondary hydroxyl groups in glycerol, leading to the favorable formation of dihydroxyacetone over glyceraldehyde and glyceric acid that were derived from the oxidation of the primary hydroxyl groups. The synergetic effect between Au and Pt demonstrates the feasibility in the efficient oxidation of glycerol to the targeted products, for example, by rational tuning of the electronic properties of metal catalysts.
基金financially supported by the Natural Science Foundation of China (21776077)the Shanghai Natural Science Foundation (17ZR1407300 and 17ZR1407500)+5 种基金the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learningthe Shanghai Rising-Star Program (17QA1401200)the Open Project of State Key Laboratory of Chemical Engineering (SKLChe-15C03)the State Key Laboratory of Organic– Inorganic Composites (oic-201801007)the Fundamental Research Funds for the Central Universities (222201718003)the 111 Project of the Ministry of Education of China (B08021)
文摘Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.
基金supported by the National Natural Science Foundation of China(12025503,U23B2072,12305329)the China Postdoctoral Science Foundation(2024T170683)the Hubei Provincial Natural Science Foundation(2023AFB236)。
文摘Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale deployment of the technology.Coupling energy-efficient electrooxidation of biomassderived glycerol and cathodic hydrogen evolution reaction provides a promising strategy for improving the techno-economics of the water electrolysis technology.Herein,by dispersing transition metal elements with weak d-p coupling strength into the MnO_(2)lattice,the fine tuning of the bioctahedral d-p orbital in MnO_(2)is successfully realized,which greatly accelerates the hydrogen transfer in glycerol oxidation.In-situ Raman results confirmed that Ni–MnO_(2)could spontaneously activate glycerol molecules and drive hydrogen transfer to lattice oxygen sites,leading to the occurrence of successive phase transitions(α-MnO_(2)→Mn_(3)O_(4)→MnOOH).Density functional theory(DFT)calculations revealed that the incorporation of Ni broadened the d-orbital and regulated the distribution of p-orbitals near the oxygen Fermi level in the lattice,resulting in a relatively high empty orbital state to facilitate the hydrogen transfer process.The optimal Ni–MnO_(2)delivered a low potential of 1.16 V vs.RHE to reach 10 mA cm^(-2),a high FE of 99.7%for formate,and superior durability over 80 h.This work provides new insights into balancing the adsorption and activation of biomass molecules while casting a universal strategy for developing efficient biomass oxidation electrocatalysts.
基金the National Science Foundation of China(No.12075002)the Outstanding Youth Fund of Anhui Province(No.2008085J21)+1 种基金Anhui Provincial Supporting Program for Excellent Young Talents in Universities(No.gxyqZD2019005)the Innovation and Entrepreneurship Project of Overseas Returnees in Anhui Province(No.2019LCX018)。
文摘Energy-saving glycerol electrolysis with lower potential than water spitting endows a promising way for the concurrent production of value-added formate and high-purity hydrogen. However, there is still lack of efficient electrocatalysts at both anode and cathode for glycerol electrolysis. Herein, we report the activation of Ni site in NiV layered double hydroxide(LDH) by electrochemical and N_(2)/H_(2) plasma regulations for boosting the activity of glycerol oxidation reaction(GOR) and hydrogen evolution reaction(HER), respectively. Specifically, boosted GOR performance with a low overpotential(1.23 V at 10 mA·cm^(-2)) and a high Faradic efficiency(94%) is demonstrated by electrochemically regulated NiV LDH(ENiV LDH) with elevated valence state of Ni site. In situ Raman spectrum reveals the generation of Ni(Ⅲ) species by electrochemical regulation, and the highly active Ni(Ⅲ)can be regenerated with the process of electrochemical oxidation. Additionally, the possible reaction pathway is speculated based on the in situ Fourier transform infrared spectroscopy(FTIR) and high-performance liquid chromatography results. The plasma-regulated NiV LDH(PNiV LDH) with lower valence state of Ni site exhibits outstanding HER activity, displaying a low overpotential of 45 m V to deliver 10 mA·cm^(-2).When employing E-NiV LDH and P-NiV LDH as anode and cathode electrocatalyst, respectively, the assembled electrolyzer merely needs 1.25 V to achieve 10 m A·cm^(-2) for simultaneous production of formate and hydrogen, demonstrating remarkable 320 mV of lower potential than water electrolysis.
