Ni-based catalysts are widely applied in the hydrodeoxygenation of lignin derivatives via C-O cleavage for the production of cycloalkanes.However,they often have difficulty in achieving high activity under mild condit...Ni-based catalysts are widely applied in the hydrodeoxygenation of lignin derivatives via C-O cleavage for the production of cycloalkanes.However,they often have difficulty in achieving high activity under mild conditions and exhibit relatively poor stability,and rare studies focus on the cleavage of the stubborn interunit C-C linkages.To address this issue,we developed a Ni@AlPO_(4)/Al_(2)O_(3)catalyst in which the surface of Ni nanoparticles was decorated by AlPO_(4)species,demonstrating excellent catalytic activity and stability in the C-C and C-O cleavages.In the hydrodeoxygenation of guaiacol,this catalyst afforded99.1%conversion and 92.9%yield of cyclohexane under 1 MPa H_(2)at 230℃ for 2 h.More important,this catalyst maintained unchanged performance even after 6 runs with the conversion controlled at about50%,Mecha nistic investigations revealed that the moderate surface coverage of AlPO_(4)on Ni with the formation of Ni^(δ+)-AlPO_(4)interface significantly facilitated the conversion of methoxycyclohexanol and cyclohexanol to cyclohexane,whereas,excess coverage would also block the access to Ni site.Moreover,Ni@AlPO_(4)/Al_(2)O_(3)demonstrated broad applicability in the C-O cleavage of various typical lignin monomers and dimers into cycloalkanes.To our delight,this catalyst also displayed pretty good activity even in the simultaneous cleavage of C-C linkages and C-O bonds for the lignin-derived C-C dimers,achieving cycloalkanes as final products.As a consequence,a 27.1 wt%yield of monocycloalkanes was obtained in the depolymerization of poplar lignin with both C-C and C-O cleavages.展开更多
Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment...Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd(Pd@NHCS-X,X:600–800)nanoreactors for catalytic HDO of biomass-derived vanillin in water.The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts.Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h^(–1)and a low apparent activation energy of 18.63 kJ/mol.The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations.It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction(EMSI)and produced numerous electron-rich active Pd centers,which not only intensified the dissociation and activation of H2 molecules,but also substantially improved the activation capability of vanillin via the enhanced adsorption of–C=O group.The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water.Additionally,the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds.The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high-performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.展开更多
In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixture...In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixtures with diverse oxygen-containing functional groups,pose a challenge as they cannot be easily separated via distillation for direct utilization.A promising solution to this challenge lies in the efficient removal of oxygen-containing functional groups from LDOs through hydrodeoxygenation(HDO),aiming to yield biomass products with singular components.However,the high dissociation energy of the carbon-oxygen bond,coupled with its similarity to the hydrogenation energy of the benzene ring,creates a competition between deoxygenation and benzene ring hydrogenation.Considering hydrogen consumption and lignin properties,the preference is directed towards generating aromatic hydrocarbons rather than saturated components.Thus,the goal is to selectively remove oxygen-containing functional groups while preserving the benzene ring structure.Studies on LDOs conversion have indicated that the design of active components and optimization of reaction conditions play pivotal roles in achieving selective deoxygenation,but a summary of the correlation between these factors and the reaction mechanism is lacking.This review addresses this gap in knowledge by firstly summarizing the various reaction pathways for HDO of LDOs.It explores the impact of catalyst design strategies,including morphology modulation,elemental doping,and surface modification,on the adsorption-desorption dynamics between reactants and catalysts.Secondly,we delve into the application of advanced techniques such as spectroscopic techniques and computational modeling,aiding in uncovering the true active sites in HDO reactions and understanding the interaction of reactive reactants with catalyst surface-interfaces.Additionally,fundamental insights into selective deoxygenation obtained through these techniques are highlighted.Finally,we outline the challenges that lie ahead in the design of highly active and selective HDO catalysts.These challenges include the development of detection tools for reactive species with high activity at low concentrations,the study of reaction medium-catalyst interactions,and the development of theoretical models that more closely approximate real reaction situations.Addressing these challenges will pave the way for the development of efficient and selective HDO catalysts,thus advancing the field of renewable LDOs conversion.展开更多
Ni-based catalysts supported on di erent supports （α-Al2O3,γ-Al2O3, SiO2, TiO2, and ZrO2） were prepared by impregnation. Effects of supports on catalytic performance were tested using hydrodeoxygenation reaction ...Ni-based catalysts supported on di erent supports （α-Al2O3,γ-Al2O3, SiO2, TiO2, and ZrO2） were prepared by impregnation. Effects of supports on catalytic performance were tested using hydrodeoxygenation reaction （HDO） of anisole as model reaction. Ni/α-Al2O3 was found to be the highest active catalyst for HDO of anisole. Under the optimal conditions, the anisole conversion is 93.25% and the hydrocarbon yield is 90.47%. Catalyst characteriza-tion using H2-TPD method demonstrates that Ni/α-Al2O3 catalyst possesses more amount of active metal Ni than those of other investigated catalysts, which can enhance the cat-alytic activity for hydrogenation. Furthermore, it is found that the Ni/α-Al2O3 catalyst has excellent repeatability, and the carbon deposited on the surface of catalyst is negligible.展开更多
Several MoS2 catalysts of different structure, prepared by in situ decomposition of ammonium heptamolybdate （AHM） and molybdenum naphthenate （MoNaph）, and by MoS2 exfoliation （TDM）, were characterized by BET, X-...Several MoS2 catalysts of different structure, prepared by in situ decomposition of ammonium heptamolybdate （AHM） and molybdenum naphthenate （MoNaph）, and by MoS2 exfoliation （TDM）, were characterized by BET, X-ray diffraction （XRD）, Energy Dispersive X-ray （EDX） and transmission electron microscopy （TEM）. The analysis showed that MoS2 structure was dependant upon the preparation procedure. The activity of the catalysts was determined by measuring the hydrodeoxygenation （HDO） of phenol, 4-methylphenol and 4-methoxyphenol using a batch autoclave reactor operated at 2.8 MPa of hydrogen and temperatures ranging from 320-370℃. By comparing the conversion, the reactivity order of the catalysts was： AHM〉TDM-D〉MoNaph〉thermal〉MoS2 powder〉 TDM-W. Also, the effect of reaction temperature on the HDO conversion was explained in terms of equilibrium of reversible reaction kinetics. The main products of the HDO for phenolic compounds were identified by gas chromatography/mass spectrometry （GC/MS）. The results showed that the product distribution and the HDO selectivity were correlated with the reaction temperature. Two parallel reaction routes, direct hydrogenolysis and combined hydrogenation-hydrogenolysis, were confirmed by the analysis of the product distribution. High temperature favored hydrogenolysis over hydrogenation for HDO of phenol and 4-methoxyphenol, whereas for 4-methylphenol the reverse was true.展开更多
The processing of an energy carrier such as microalgae oil into valuable fuels and chemicals is quite promising.Aqueous-phase processing is suitable for this purpose because the separation of intrinsic water from the ...The processing of an energy carrier such as microalgae oil into valuable fuels and chemicals is quite promising.Aqueous-phase processing is suitable for this purpose because the separation of intrinsic water from the algae cell is difficult.In this study,we synthesized ruthenium(Ru)nanoparticles supported on highly hydrophilic mesoporous carbon to catalyze the quantitative hydrodeoxygenation(HDO)of microalgae oil to alkanes in a one-pot process at a low temperature(140℃)in the aqueous phase.The mesoporous carbon was obtained by single-step calcination of starch and zinc chloride in nitrogen.The as-obtained carbon showed high surface areas and pore volumes,allowing high dispersion of Ru nanoparticles.The surface of the carbon material was rich in hydroxyl groups,as evidenced by X-ray photoelectron spectroscopy(XPS),infrared(IR)spectroscopy,and thermogravimetric analysis(TGA)measurements.As a result,the carbon material contacted preferably with the water phase versus the organic phase,improving the accessibility of substrates.On the other hand,the contact angle test results speculated the superior hydrophilic nature of mesoporous Ru/C(ZnCl2,starch)than commercial Ru/C.Both kinetics modeling and in situ IR monitoring in water revealed the superior performance of the hydrophilic mesoporous and hydrophilic Ru/C compared to a commercial Ru/C for the tandem hydrogenation of stearic acid and decarbonylation of stearyl alcohol.The herein designed hydrothermal carbon material was highly active,environmentally benign,sustainable,and recyclable material,and could be potentially used for other hydrogenation reactions in the aqueous phase.展开更多
NiP/SiOand bimetallic Ni MP/Si O2(M = Co, Fe, Mo, W; Ni/M atomic ratio=5) catalysts were prepared by the temperature-programmed reduction method. The catalysts and their precursors were characterized by means of UV–V...NiP/SiOand bimetallic Ni MP/Si O2(M = Co, Fe, Mo, W; Ni/M atomic ratio=5) catalysts were prepared by the temperature-programmed reduction method. The catalysts and their precursors were characterized by means of UV–Vis DRS, H-TPR, XRD, TEM, CO chemisorption and NH-TPD. Their performance for the deoxygenation of methyl laurate was tested on a fixed-bed reactor. The results show that the main phase was NiP in all catalysts, and M(M = Co, Fe, Mo, W) entered the lattice of NiP forming solid solution. Different from Fe and Co, the introduction of Mo and W into NiP/SiOreduced the phosphide particle size and increased the acid amount. In the deoxygenation reaction, the turnover frequency of methyl laurate increased on the catalysts in the order of NiMoP/SiO, NiP/SiO, Ni WP/Si O2, NiFeP/SiOand NiCoP/SiO, which is influenced by the size of phosphide particles and the interaction between Ni and M(M = Fe, Co, Mo or W). The introduction of the second metal(especially Mo and W) into NiP/SiOpromoted the hydrodeoxygenation pathway. This is mainly attributed to the interaction between Ni and the second metal. Finally, the Ni MoP/SiOcatalyst was tested at 340 oC, 3 MPa, methyl laurate WHSV of 14 h-1and H/methyl laurate molar ratio of 25 for 132 h, and its deactivation took place. We found that the catalyst deactivation mainly resulted from carbonaceous deposit rather than the sintering of metal phosphide crystallites.展开更多
Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficien...Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.展开更多
The supported Pt catalysts(1 wt%)were prepared by the incipient impregnation method and analyzed using synchrotron-based X-ray diffraction,BET surface area,oxygen adsorption,CO pulse chemisorption,temperature-programm...The supported Pt catalysts(1 wt%)were prepared by the incipient impregnation method and analyzed using synchrotron-based X-ray diffraction,BET surface area,oxygen adsorption,CO pulse chemisorption,temperature-programmed desorption(TPD)of acetic acid,H2-TPD,NH3-TPD,O2-TPD,and H2-TPR.The reactivity of Pt-based catalysts was studied using a fixed bed reactor at 300 C and 4 MPa for hydrodeoxygenation of acetic acid,where Pt/TiO2 was very selective for ethane production.TPD experiments revealed that several conditions must be satisfied to achieve this high selectivity to ethane from acetic acid,such as Pt sites,moderate acidity,and medium metal-oxygen bond strength in the oxide support.This work provides insights in developing novel catalytic materials for hydrocarbon productions from various organics including bio-fuels.展开更多
Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O c...Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.展开更多
The use of silver metal for hydrodeoxygenation(HDO) applications is scarce and different studies have indicated of its varying HDO activity. Several computational studies have reported of silver having almost zero tur...The use of silver metal for hydrodeoxygenation(HDO) applications is scarce and different studies have indicated of its varying HDO activity. Several computational studies have reported of silver having almost zero turnover frequency for HDO owing to its high C\\O bond breaking energy barrier and low carbon and oxygen binding energies.Herein this work, titania supported silver catalysts were synthesized and firstly used to examine its phenol HDO activity via experimental reaction runs. BET, XRD, FESEM, TEM, EDX, ICP–OES, Pyridine-FTIR, NH_3-TPD and H_2-TPD analyses were done to investigate its physicochemical properties. Phenomena of hydrogen spillover and metal–acid site synergy were examined in this study. With the aid of TiO_2 reducible support, hydrogen spillover and metal–acid site interactions were observed to a certain extent but were not as superior as other Pt, Pd, Ni-based catalysts used in other HDO studies. The experimental findings showed that Ag/TiO_2 catalyst has mediocre phenol conversion but high benzene selectivity which confirms the explanation from other computational studies.展开更多
Catalytic hydrodeoxygenation(HDO)is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons.Herein,an efficient bimetallic catalyst Pt_(1)Ni_(4)/MgO ...Catalytic hydrodeoxygenation(HDO)is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons.Herein,an efficient bimetallic catalyst Pt_(1)Ni_(4)/MgO was prepared and applied in the HDO of dibenzofuran(DBF).High yield(95%)of the desired product bicyclohexane(BCH)was achieved at 240℃and 1.2 MPa of H_(2).Superior catalytic performance could be ascribed to the"relay catalysis"of Pt sites and Ni sites,and the reaction pathway is proposed as well.Scale-up experiment and recyclability test were also performed,which demonstrated the recyclability and promising potential application of Pt_(1)Ni_(4)/MgO.展开更多
Hydrodeoxygenation(HDO)is one of the most promising strategies for the upgrading of biomass-derived compounds to chemicals and fuels.However,the conventional HDO process accompanied by insecure high-pressure H_(2)lead...Hydrodeoxygenation(HDO)is one of the most promising strategies for the upgrading of biomass-derived compounds to chemicals and fuels.However,the conventional HDO process accompanied by insecure high-pressure H_(2)leads to the hefty infrastructure cost on the industrial scale and inevitably trigger overall hydrogenation which is considered as an uncontrollable and risky approach.Accordingly,the developments of alcohol-assisted HDO can be viewed as a sustainable and cost-effective alternative.This review critically summarizes the potentials and challenges of alcohol-assisted strategy from diverse perspectives including safety,economics and catalytic efficiency.Based on the discrepancies of in-situ hydrogen generation,the alcohol-assisted strategy is divided into combined reforming-HDO route and catalytic transfer hydrogenation/hydrogenolysis(CTH)route.Furthermore,describe different catalytic behaviors and elaborate their applications among several upgrading processes of representative biomass model compounds,aiming to illustrate their potentials in biomass utilization.The influence of alcohols is highlighted because they act both hydrogen donor and solvent.At last,the current challenges and perspectives of alcohol-assisted HDO are proposed for further development and improvement.展开更多
Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or i...Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a challenge.Herein,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived anisole.Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes selectivity.As a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).展开更多
The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst wa...The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.展开更多
SiO2‐supported monometallic Ni and bimetallic Ni‐In catalysts were prepared and used for hydrodeoxygenation of anisole,which was used as a model bio‐oil compound,for BTX(benzene,toluene,and xylene)production.The ef...SiO2‐supported monometallic Ni and bimetallic Ni‐In catalysts were prepared and used for hydrodeoxygenation of anisole,which was used as a model bio‐oil compound,for BTX(benzene,toluene,and xylene)production.The effects of the Ni/In ratio and Ni content on the structures and performances of the catalysts were investigated.The results show that In atoms were incorporated into the Ni metal lattice.Although the Ni‐In bimetallic crystallites were similar in size to those of monometallic Ni at the same Ni content,H2uptake by the bimetallic Ni‐In catalyst was much lower than that by monometallic Ni because of dilution of Ni atoms by In atoms.Charge transfer from In to Ni was observed for the bimetallic Ni‐In catalysts.All the results indicate intimate contact between Ni and In atoms,and the In atoms geometrically and electronically modified the Ni atoms.In the hydrodeoxygenation of anisole,although the activities of the Ni‐In bimetallic catalysts in the conversion of anisole were lower than that of the monometallic Ni catalyst,they gave higher selectivities for BTX and cyclohexane as a result of suppression of benzene ring hydrogenation and C–C bond hydrogenolysis.They also showed lower methanation activity.These results will be useful for enhancing carbon yields and reducing H2consumption.In addition,the lower the Ni/In ratio was,the greater was the effect of In on the catalytic performance.The selectivity for BTX was primarily determined by the Ni/In ratio and was little affected by the Ni content.We suggest that the performance of the Ni‐In bimetallic catalyst can be ascribed to the geometric and electronic effects of In.展开更多
Bulk Ni-Mo composites were prepared by a simple solid reaction method and the hydrodeoxygenation activity of samples was examined. The test results showed that the Ni-Mo catalysts possessed high catalytic activity for...Bulk Ni-Mo composites were prepared by a simple solid reaction method and the hydrodeoxygenation activity of samples was examined. The test results showed that the Ni-Mo catalysts possessed high catalytic activity for hydrogenation of p-cresol under mild conditions. The XRD, N_2 isothermal adsorption, NH_3-TPD characterization analyses indicated that the excellent hydrogenation performance of Ni-Mo catalysts could be attributed to their incorporated Mo metal, the developed pore system, and the strong acidity.展开更多
The effect of ethanedioic acid（Ed A） functionalization on Al2O3 supported Ni catalyst was studied on the hydrodeoxygenation（HDO）, isomerization, kinetics and Arrhenius parameters of octadec-9-enoic acid（OA） into...The effect of ethanedioic acid（Ed A） functionalization on Al2O3 supported Ni catalyst was studied on the hydrodeoxygenation（HDO）, isomerization, kinetics and Arrhenius parameters of octadec-9-enoic acid（OA） into biofuel in this report. This was achieved via synthesis of two catalysts; the first, nickel alumina catalyst（Ni/Al2O3） was via the incorporation of inorganic Ni precursor into Al2O3; the second was via the incorporation nickel oxalate（Ni Ox） prepared by functionalization of Ni with Ed A into Al2O3 to obtain organometallic Ni Ox/Al2O3 catalyst. Their characterization results showed that Ni species present in Ni/Al2O3 and Ni Ox/Al2O3 were 8.2% and 9.3%, respectively according to the energy dispersive X-ray result. Ni Ox/Al2O3 has comparably higher Ni content due to the Ed A functionalization which also increases its acidity and guarantees high Ni dispersion with weaker metal-support-interaction leading to highly reducible Ni as seen in the X-ray diffraction, X-ray photoelectron spectroscopy, TPR and Raman spectroscopy results. Their activities tested on the HDO of OA showed that Ni Ox/Al2O3 did not only display the best catalytic and reusability abilities, but it also possesses isomerization ability due to its increased acidity. The Ni Ox/Al2O3 also has the highest rate constants evaluated using pseudo-first-order kinetics,but the least activation energy of 176 k J/mol in the biofuel formation step compared to 244 k J/mol evaluated when using Ni/Al2O3. The result is promising for future feasibility studies toward commercialization of catalytic HDO of OA into useful biofuel using organometallic catalysts.展开更多
Two series of bimetallic Ni-Co catalysts and corresponding monometallic catalysts with ca. 20 wt% metal loading were evaluated in hydrodeoxygenation (HDO) of phenol as a model compound for bio-oil. The bimetallic cata...Two series of bimetallic Ni-Co catalysts and corresponding monometallic catalysts with ca. 20 wt% metal loading were evaluated in hydrodeoxygenation (HDO) of phenol as a model compound for bio-oil. The bimetallic catalysts outperformed the corresponding monometallic catalyst in terms of conversion and cyclohexane selectivity. This could be attributed to the formation of Ni-Co alloy, which caused a decrease in metal particle size and stabilized Ni active sites in the near surface region. The balanced combination of formed Ni-Co alloy with acidity from supports allowed performing all individual steps in the reaction network toward desired products at high rate. Consequently, the two best-performing catalysts were tested in HDO of wood based bio-oil, showing that the bimetallic catalyst 10Ni10Co/HZSM-5 was more effective than 20Ni/HZSM-5 in terms of degree of deoxygenation and upgraded bio-oil yield. These findings might open an opportunity for development of a novel cheap but effective catalyst for a key step in the process chain from biomass to renewable liquid fuels.展开更多
In this study, inhibition of tall oil fatty acid hydrodeoxygenation(HDO) activity due to addition of rosin acid over sulfided Ni Mo/Al_2O_3 was investigated. Oleic acid and abietic acid were used as model compounds fo...In this study, inhibition of tall oil fatty acid hydrodeoxygenation(HDO) activity due to addition of rosin acid over sulfided Ni Mo/Al_2O_3 was investigated. Oleic acid and abietic acid were used as model compounds for fatty acid and rosin acid respectively in tall oil. After completion of each HDO experiment,the Ni Mo catalysts were recovered and used again under the same conditions. The results showed that the oleic acid HDO activity of sulfided catalysts was inhibited by addition of abietic acid due to competitive adsorption and increased coke deposition. The rate of carbon deposition on the catalysts increased when abietic acid was added to oleic acid feed. Moreover, the coke was in a more advanced form with higher stability for the catalysts exposed to both oleic acid and abietic acid. Furthermore, a clear correlation between the rate of coke formation and concentration of abietic acid was observed.展开更多
基金supported by National Natural Science Foundation of China(22178258,22308254)China Postdoctoral Science Foundation(2023M742593,2024T170642)+1 种基金Independent Innova-tion Fund of Tianjin University(2024XQM-0021)the Open Fund of the Key Laboratory of Functional Molecular Solids(FMS2023006)。
文摘Ni-based catalysts are widely applied in the hydrodeoxygenation of lignin derivatives via C-O cleavage for the production of cycloalkanes.However,they often have difficulty in achieving high activity under mild conditions and exhibit relatively poor stability,and rare studies focus on the cleavage of the stubborn interunit C-C linkages.To address this issue,we developed a Ni@AlPO_(4)/Al_(2)O_(3)catalyst in which the surface of Ni nanoparticles was decorated by AlPO_(4)species,demonstrating excellent catalytic activity and stability in the C-C and C-O cleavages.In the hydrodeoxygenation of guaiacol,this catalyst afforded99.1%conversion and 92.9%yield of cyclohexane under 1 MPa H_(2)at 230℃ for 2 h.More important,this catalyst maintained unchanged performance even after 6 runs with the conversion controlled at about50%,Mecha nistic investigations revealed that the moderate surface coverage of AlPO_(4)on Ni with the formation of Ni^(δ+)-AlPO_(4)interface significantly facilitated the conversion of methoxycyclohexanol and cyclohexanol to cyclohexane,whereas,excess coverage would also block the access to Ni site.Moreover,Ni@AlPO_(4)/Al_(2)O_(3)demonstrated broad applicability in the C-O cleavage of various typical lignin monomers and dimers into cycloalkanes.To our delight,this catalyst also displayed pretty good activity even in the simultaneous cleavage of C-C linkages and C-O bonds for the lignin-derived C-C dimers,achieving cycloalkanes as final products.As a consequence,a 27.1 wt%yield of monocycloalkanes was obtained in the depolymerization of poplar lignin with both C-C and C-O cleavages.
文摘Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation(HDO)of biomass-derived oxygenates to value-added biofuels is highly desired.An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd(Pd@NHCS-X,X:600–800)nanoreactors for catalytic HDO of biomass-derived vanillin in water.The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts.Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h^(–1)and a low apparent activation energy of 18.63 kJ/mol.The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations.It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction(EMSI)and produced numerous electron-rich active Pd centers,which not only intensified the dissociation and activation of H2 molecules,but also substantially improved the activation capability of vanillin via the enhanced adsorption of–C=O group.The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water.Additionally,the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds.The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high-performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.
基金supported by the National Natural Science Foundation of China,Pilot Group Program of the Research Fund for International Senior Scientists(22250710676)National Natural Science Foundation of China(22078064,22378062,22304028)+1 种基金Natural Science Foundation of Fujian Province(2021J02009)Tianjin University-Fuzhou University Independent Innovation Fund Cooperation Project(TF2023-1,TF2023-8).
文摘In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixtures with diverse oxygen-containing functional groups,pose a challenge as they cannot be easily separated via distillation for direct utilization.A promising solution to this challenge lies in the efficient removal of oxygen-containing functional groups from LDOs through hydrodeoxygenation(HDO),aiming to yield biomass products with singular components.However,the high dissociation energy of the carbon-oxygen bond,coupled with its similarity to the hydrogenation energy of the benzene ring,creates a competition between deoxygenation and benzene ring hydrogenation.Considering hydrogen consumption and lignin properties,the preference is directed towards generating aromatic hydrocarbons rather than saturated components.Thus,the goal is to selectively remove oxygen-containing functional groups while preserving the benzene ring structure.Studies on LDOs conversion have indicated that the design of active components and optimization of reaction conditions play pivotal roles in achieving selective deoxygenation,but a summary of the correlation between these factors and the reaction mechanism is lacking.This review addresses this gap in knowledge by firstly summarizing the various reaction pathways for HDO of LDOs.It explores the impact of catalyst design strategies,including morphology modulation,elemental doping,and surface modification,on the adsorption-desorption dynamics between reactants and catalysts.Secondly,we delve into the application of advanced techniques such as spectroscopic techniques and computational modeling,aiding in uncovering the true active sites in HDO reactions and understanding the interaction of reactive reactants with catalyst surface-interfaces.Additionally,fundamental insights into selective deoxygenation obtained through these techniques are highlighted.Finally,we outline the challenges that lie ahead in the design of highly active and selective HDO catalysts.These challenges include the development of detection tools for reactive species with high activity at low concentrations,the study of reaction medium-catalyst interactions,and the development of theoretical models that more closely approximate real reaction situations.Addressing these challenges will pave the way for the development of efficient and selective HDO catalysts,thus advancing the field of renewable LDOs conversion.
文摘Ni-based catalysts supported on di erent supports （α-Al2O3,γ-Al2O3, SiO2, TiO2, and ZrO2） were prepared by impregnation. Effects of supports on catalytic performance were tested using hydrodeoxygenation reaction （HDO） of anisole as model reaction. Ni/α-Al2O3 was found to be the highest active catalyst for HDO of anisole. Under the optimal conditions, the anisole conversion is 93.25% and the hydrocarbon yield is 90.47%. Catalyst characteriza-tion using H2-TPD method demonstrates that Ni/α-Al2O3 catalyst possesses more amount of active metal Ni than those of other investigated catalysts, which can enhance the cat-alytic activity for hydrogenation. Furthermore, it is found that the Ni/α-Al2O3 catalyst has excellent repeatability, and the carbon deposited on the surface of catalyst is negligible.
文摘Several MoS2 catalysts of different structure, prepared by in situ decomposition of ammonium heptamolybdate （AHM） and molybdenum naphthenate （MoNaph）, and by MoS2 exfoliation （TDM）, were characterized by BET, X-ray diffraction （XRD）, Energy Dispersive X-ray （EDX） and transmission electron microscopy （TEM）. The analysis showed that MoS2 structure was dependant upon the preparation procedure. The activity of the catalysts was determined by measuring the hydrodeoxygenation （HDO） of phenol, 4-methylphenol and 4-methoxyphenol using a batch autoclave reactor operated at 2.8 MPa of hydrogen and temperatures ranging from 320-370℃. By comparing the conversion, the reactivity order of the catalysts was： AHM〉TDM-D〉MoNaph〉thermal〉MoS2 powder〉 TDM-W. Also, the effect of reaction temperature on the HDO conversion was explained in terms of equilibrium of reversible reaction kinetics. The main products of the HDO for phenolic compounds were identified by gas chromatography/mass spectrometry （GC/MS）. The results showed that the product distribution and the HDO selectivity were correlated with the reaction temperature. Two parallel reaction routes, direct hydrogenolysis and combined hydrogenation-hydrogenolysis, were confirmed by the analysis of the product distribution. High temperature favored hydrogenolysis over hydrogenation for HDO of phenol and 4-methoxyphenol, whereas for 4-methylphenol the reverse was true.
文摘The processing of an energy carrier such as microalgae oil into valuable fuels and chemicals is quite promising.Aqueous-phase processing is suitable for this purpose because the separation of intrinsic water from the algae cell is difficult.In this study,we synthesized ruthenium(Ru)nanoparticles supported on highly hydrophilic mesoporous carbon to catalyze the quantitative hydrodeoxygenation(HDO)of microalgae oil to alkanes in a one-pot process at a low temperature(140℃)in the aqueous phase.The mesoporous carbon was obtained by single-step calcination of starch and zinc chloride in nitrogen.The as-obtained carbon showed high surface areas and pore volumes,allowing high dispersion of Ru nanoparticles.The surface of the carbon material was rich in hydroxyl groups,as evidenced by X-ray photoelectron spectroscopy(XPS),infrared(IR)spectroscopy,and thermogravimetric analysis(TGA)measurements.As a result,the carbon material contacted preferably with the water phase versus the organic phase,improving the accessibility of substrates.On the other hand,the contact angle test results speculated the superior hydrophilic nature of mesoporous Ru/C(ZnCl2,starch)than commercial Ru/C.Both kinetics modeling and in situ IR monitoring in water revealed the superior performance of the hydrophilic mesoporous and hydrophilic Ru/C compared to a commercial Ru/C for the tandem hydrogenation of stearic acid and decarbonylation of stearyl alcohol.The herein designed hydrothermal carbon material was highly active,environmentally benign,sustainable,and recyclable material,and could be potentially used for other hydrogenation reactions in the aqueous phase.
基金financially supported by the National Natural Science Foundation of China(No.21176177)the Natural Science Foundation of Tianjin(No.12JCYBJC13200)
文摘NiP/SiOand bimetallic Ni MP/Si O2(M = Co, Fe, Mo, W; Ni/M atomic ratio=5) catalysts were prepared by the temperature-programmed reduction method. The catalysts and their precursors were characterized by means of UV–Vis DRS, H-TPR, XRD, TEM, CO chemisorption and NH-TPD. Their performance for the deoxygenation of methyl laurate was tested on a fixed-bed reactor. The results show that the main phase was NiP in all catalysts, and M(M = Co, Fe, Mo, W) entered the lattice of NiP forming solid solution. Different from Fe and Co, the introduction of Mo and W into NiP/SiOreduced the phosphide particle size and increased the acid amount. In the deoxygenation reaction, the turnover frequency of methyl laurate increased on the catalysts in the order of NiMoP/SiO, NiP/SiO, Ni WP/Si O2, NiFeP/SiOand NiCoP/SiO, which is influenced by the size of phosphide particles and the interaction between Ni and M(M = Fe, Co, Mo or W). The introduction of the second metal(especially Mo and W) into NiP/SiOpromoted the hydrodeoxygenation pathway. This is mainly attributed to the interaction between Ni and the second metal. Finally, the Ni MoP/SiOcatalyst was tested at 340 oC, 3 MPa, methyl laurate WHSV of 14 h-1and H/methyl laurate molar ratio of 25 for 132 h, and its deactivation took place. We found that the catalyst deactivation mainly resulted from carbonaceous deposit rather than the sintering of metal phosphide crystallites.
文摘Catalytic hydrodeoxygenation(HDO)is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels,but highly challenging due to the lack of highly efficient nonprecious metal catalysts.Herein,we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst.The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100%conversion efficiency and selectivity under mild reaction conditions,surpassing the reported high performance nonprecious HDO catalysts.Impressively,our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100%conversion efficiency and over 90%selectivity.Importantly,our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O,and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs.The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.
文摘The supported Pt catalysts(1 wt%)were prepared by the incipient impregnation method and analyzed using synchrotron-based X-ray diffraction,BET surface area,oxygen adsorption,CO pulse chemisorption,temperature-programmed desorption(TPD)of acetic acid,H2-TPD,NH3-TPD,O2-TPD,and H2-TPR.The reactivity of Pt-based catalysts was studied using a fixed bed reactor at 300 C and 4 MPa for hydrodeoxygenation of acetic acid,where Pt/TiO2 was very selective for ethane production.TPD experiments revealed that several conditions must be satisfied to achieve this high selectivity to ethane from acetic acid,such as Pt sites,moderate acidity,and medium metal-oxygen bond strength in the oxide support.This work provides insights in developing novel catalytic materials for hydrocarbon productions from various organics including bio-fuels.
基金supported by the National Key R&D Program of China(2021YFC2103704)the National Natural Science Foundation of China(22022812,21978259)+1 种基金Key R&D Program of Zhejiang(2022C01208)Institute of Zhejiang University-Quzhou S&T Planed Projects(IZQ2021KJ1001)。
文摘Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.
基金GSP-MOHE,University of Malaya for fully funding this study through the project number "MO008-2015"Ministry of Higher Education of Malaysia (MOHE) for MyBrain15 (MyPhD) programIPPP for project "PG081-2016A"
文摘The use of silver metal for hydrodeoxygenation(HDO) applications is scarce and different studies have indicated of its varying HDO activity. Several computational studies have reported of silver having almost zero turnover frequency for HDO owing to its high C\\O bond breaking energy barrier and low carbon and oxygen binding energies.Herein this work, titania supported silver catalysts were synthesized and firstly used to examine its phenol HDO activity via experimental reaction runs. BET, XRD, FESEM, TEM, EDX, ICP–OES, Pyridine-FTIR, NH_3-TPD and H_2-TPD analyses were done to investigate its physicochemical properties. Phenomena of hydrogen spillover and metal–acid site synergy were examined in this study. With the aid of TiO_2 reducible support, hydrogen spillover and metal–acid site interactions were observed to a certain extent but were not as superior as other Pt, Pd, Ni-based catalysts used in other HDO studies. The experimental findings showed that Ag/TiO_2 catalyst has mediocre phenol conversion but high benzene selectivity which confirms the explanation from other computational studies.
基金Key Laboratory of Biomass Energy and Material,Jiangsu Province(No.JSBEM201912)Chinese Postdoctoral Science Foundation(Nos.2015M571761 and 2016T90465)for financial support+1 种基金funded by the Priority Academic Program Development of Jiangsu Higher Education InstitutionInstrument and Equipment Foundation of Nanjing University of Science&Technology。
文摘Catalytic hydrodeoxygenation(HDO)is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons.Herein,an efficient bimetallic catalyst Pt_(1)Ni_(4)/MgO was prepared and applied in the HDO of dibenzofuran(DBF).High yield(95%)of the desired product bicyclohexane(BCH)was achieved at 240℃and 1.2 MPa of H_(2).Superior catalytic performance could be ascribed to the"relay catalysis"of Pt sites and Ni sites,and the reaction pathway is proposed as well.Scale-up experiment and recyclability test were also performed,which demonstrated the recyclability and promising potential application of Pt_(1)Ni_(4)/MgO.
基金Financial support from the National Natural Science Foundation of China(22108056)the Scientific Research Projects of Hebei Education Department(QN2019050)the Natural Science Foundation of Hebei Province(B2020202004)。
文摘Hydrodeoxygenation(HDO)is one of the most promising strategies for the upgrading of biomass-derived compounds to chemicals and fuels.However,the conventional HDO process accompanied by insecure high-pressure H_(2)leads to the hefty infrastructure cost on the industrial scale and inevitably trigger overall hydrogenation which is considered as an uncontrollable and risky approach.Accordingly,the developments of alcohol-assisted HDO can be viewed as a sustainable and cost-effective alternative.This review critically summarizes the potentials and challenges of alcohol-assisted strategy from diverse perspectives including safety,economics and catalytic efficiency.Based on the discrepancies of in-situ hydrogen generation,the alcohol-assisted strategy is divided into combined reforming-HDO route and catalytic transfer hydrogenation/hydrogenolysis(CTH)route.Furthermore,describe different catalytic behaviors and elaborate their applications among several upgrading processes of representative biomass model compounds,aiming to illustrate their potentials in biomass utilization.The influence of alcohols is highlighted because they act both hydrogen donor and solvent.At last,the current challenges and perspectives of alcohol-assisted HDO are proposed for further development and improvement.
基金supported by National Natural Science Foundation of China (21938008).
文摘Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a challenge.Herein,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived anisole.Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes selectivity.As a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).
文摘The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.
基金supported by the National Natural Science Foundation of China(21576193,21176177)~~
文摘SiO2‐supported monometallic Ni and bimetallic Ni‐In catalysts were prepared and used for hydrodeoxygenation of anisole,which was used as a model bio‐oil compound,for BTX(benzene,toluene,and xylene)production.The effects of the Ni/In ratio and Ni content on the structures and performances of the catalysts were investigated.The results show that In atoms were incorporated into the Ni metal lattice.Although the Ni‐In bimetallic crystallites were similar in size to those of monometallic Ni at the same Ni content,H2uptake by the bimetallic Ni‐In catalyst was much lower than that by monometallic Ni because of dilution of Ni atoms by In atoms.Charge transfer from In to Ni was observed for the bimetallic Ni‐In catalysts.All the results indicate intimate contact between Ni and In atoms,and the In atoms geometrically and electronically modified the Ni atoms.In the hydrodeoxygenation of anisole,although the activities of the Ni‐In bimetallic catalysts in the conversion of anisole were lower than that of the monometallic Ni catalyst,they gave higher selectivities for BTX and cyclohexane as a result of suppression of benzene ring hydrogenation and C–C bond hydrogenolysis.They also showed lower methanation activity.These results will be useful for enhancing carbon yields and reducing H2consumption.In addition,the lower the Ni/In ratio was,the greater was the effect of In on the catalytic performance.The selectivity for BTX was primarily determined by the Ni/In ratio and was little affected by the Ni content.We suggest that the performance of the Ni‐In bimetallic catalyst can be ascribed to the geometric and electronic effects of In.
基金supported by grants from the National Natural Science Foundation of China(No. 21306106)the Open Foundation of the State Key Laboratory of Bioactive Seaweed Substances,Qingdao Brightmoon Seaweed Group Co., Ltd.(No. SKL-BASS1723)
文摘Bulk Ni-Mo composites were prepared by a simple solid reaction method and the hydrodeoxygenation activity of samples was examined. The test results showed that the Ni-Mo catalysts possessed high catalytic activity for hydrogenation of p-cresol under mild conditions. The XRD, N_2 isothermal adsorption, NH_3-TPD characterization analyses indicated that the excellent hydrogenation performance of Ni-Mo catalysts could be attributed to their incorporated Mo metal, the developed pore system, and the strong acidity.
基金financial support from Higher Impact Research-Ministry of Higher Education project no D000011-16001 of the Faculty of Engineering,University of Malaya,Malaysia and the Mitsubishi Corporation Education Trust Fund,University Teknologi PETRONAS,Malaysia
文摘The effect of ethanedioic acid（Ed A） functionalization on Al2O3 supported Ni catalyst was studied on the hydrodeoxygenation（HDO）, isomerization, kinetics and Arrhenius parameters of octadec-9-enoic acid（OA） into biofuel in this report. This was achieved via synthesis of two catalysts; the first, nickel alumina catalyst（Ni/Al2O3） was via the incorporation of inorganic Ni precursor into Al2O3; the second was via the incorporation nickel oxalate（Ni Ox） prepared by functionalization of Ni with Ed A into Al2O3 to obtain organometallic Ni Ox/Al2O3 catalyst. Their characterization results showed that Ni species present in Ni/Al2O3 and Ni Ox/Al2O3 were 8.2% and 9.3%, respectively according to the energy dispersive X-ray result. Ni Ox/Al2O3 has comparably higher Ni content due to the Ed A functionalization which also increases its acidity and guarantees high Ni dispersion with weaker metal-support-interaction leading to highly reducible Ni as seen in the X-ray diffraction, X-ray photoelectron spectroscopy, TPR and Raman spectroscopy results. Their activities tested on the HDO of OA showed that Ni Ox/Al2O3 did not only display the best catalytic and reusability abilities, but it also possesses isomerization ability due to its increased acidity. The Ni Ox/Al2O3 also has the highest rate constants evaluated using pseudo-first-order kinetics,but the least activation energy of 176 k J/mol in the biofuel formation step compared to 244 k J/mol evaluated when using Ni/Al2O3. The result is promising for future feasibility studies toward commercialization of catalytic HDO of OA into useful biofuel using organometallic catalysts.
文摘Two series of bimetallic Ni-Co catalysts and corresponding monometallic catalysts with ca. 20 wt% metal loading were evaluated in hydrodeoxygenation (HDO) of phenol as a model compound for bio-oil. The bimetallic catalysts outperformed the corresponding monometallic catalyst in terms of conversion and cyclohexane selectivity. This could be attributed to the formation of Ni-Co alloy, which caused a decrease in metal particle size and stabilized Ni active sites in the near surface region. The balanced combination of formed Ni-Co alloy with acidity from supports allowed performing all individual steps in the reaction network toward desired products at high rate. Consequently, the two best-performing catalysts were tested in HDO of wood based bio-oil, showing that the bimetallic catalyst 10Ni10Co/HZSM-5 was more effective than 20Ni/HZSM-5 in terms of degree of deoxygenation and upgraded bio-oil yield. These findings might open an opportunity for development of a novel cheap but effective catalyst for a key step in the process chain from biomass to renewable liquid fuels.
基金Formas (Contracts: 239-2012-1584 and 239-2014-164) and Preem for the financial support
文摘In this study, inhibition of tall oil fatty acid hydrodeoxygenation(HDO) activity due to addition of rosin acid over sulfided Ni Mo/Al_2O_3 was investigated. Oleic acid and abietic acid were used as model compounds for fatty acid and rosin acid respectively in tall oil. After completion of each HDO experiment,the Ni Mo catalysts were recovered and used again under the same conditions. The results showed that the oleic acid HDO activity of sulfided catalysts was inhibited by addition of abietic acid due to competitive adsorption and increased coke deposition. The rate of carbon deposition on the catalysts increased when abietic acid was added to oleic acid feed. Moreover, the coke was in a more advanced form with higher stability for the catalysts exposed to both oleic acid and abietic acid. Furthermore, a clear correlation between the rate of coke formation and concentration of abietic acid was observed.
