The electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF)offers a promising approach for producing high-value chemicals and hydrogen.While cobalt-based oxides are promising catalysts for the HMF oxidation reactio...The electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF)offers a promising approach for producing high-value chemicals and hydrogen.While cobalt-based oxides are promising catalysts for the HMF oxidation reaction(HMFOR),their performance is limited by inefficient oxidation of CoO_(x)to the active CoO_(2)phase.Here,we demonstrate that introducing oxygen vacancies into CoO_(x)significantly enhances its oxidation kinetics.The oxygen vacancy-rich CoO_(x)supported on copper foam(CoO_(x)/CF)achieves an impressive 98%HMF conversion with a Faradaic efficiency of 98.6%at 1.5 V vs.RHE.Operando Raman spectroscopy reveals that oxygen vacancies facilitate the preferential formation ofγ-CoOOH overβ-CoOOH during electrocatalysis,thereby promoting the generation of the active CoO_(2)phase.Combining in situ infrared spectroscopy with density functional theory(DFT)calculations,we unambiguously establish the reaction pathway,which proceeds via the sequence of HMF→5-hydroxymethyl-2-fur ancarboxylic acid(HMFCA)→2-formyl-5-furancarboxylic acid(FFCA)→2,5-furandicarboxylic acid(FDCA),and reveal the pivotal role of the active CoO_(2)species in accelerating hydroxyl radical oxidation.This work not only provides fundamental mechanistic insights into oxygen vacancy-mediated catalyst design but also offers a novel strategy for developing high-performance transition metal oxide electrocatalysts for biomass valorization.展开更多
Achieving high selectivity to 2,5-furandicarboxylic acid(FDCA)in the photocatalytic oxidation of 5-hydroxymethylfurfural(HMF)in aqueous solution advocates the principle of green and sustainable chemistry,but still rem...Achieving high selectivity to 2,5-furandicarboxylic acid(FDCA)in the photocatalytic oxidation of 5-hydroxymethylfurfural(HMF)in aqueous solution advocates the principle of green and sustainable chemistry,but still remains a significant challenge.Herein,manipulating the reactive oxygen species(ROS)has been realized and dramatically promotes the selective photocatalytic oxidation of HMF in aqueous solution.A high FDCAyield of 98.6% has been achieved after 3 h of visible light irradiation over the as-prepared FeO_(x)-Au/TiO_(2) catalyst,being one of the leading photocatalytic performances.Furthermore,satisfactory FDCA yields of higher than 80%could be realized even in the outdoor environment under natural sunlight irradiation,regardless of sunny or cloudy weather.A combination study including physical characterization,kinetic analysis,radical trapping experiments and density functional theory calculations unveils the rate-determining step(oxidation of hydroxyl group)and respective contributions of the generated ROS(1O_(2) and·O_(2)-)in each step of the entire reaction network.The present work would push ahead the understanding of HMF photocatalytic oxidation and contribute to the rational design of high-performance photocatalysts.展开更多
Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via lo...Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.22308246,22478278)the Central Government Guides the Local Science and Technology Development Special Fund(No.YDZJSX20231A015)the Fundamental Research Program of Shanxi Province(No.202203021212266)。
文摘The electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF)offers a promising approach for producing high-value chemicals and hydrogen.While cobalt-based oxides are promising catalysts for the HMF oxidation reaction(HMFOR),their performance is limited by inefficient oxidation of CoO_(x)to the active CoO_(2)phase.Here,we demonstrate that introducing oxygen vacancies into CoO_(x)significantly enhances its oxidation kinetics.The oxygen vacancy-rich CoO_(x)supported on copper foam(CoO_(x)/CF)achieves an impressive 98%HMF conversion with a Faradaic efficiency of 98.6%at 1.5 V vs.RHE.Operando Raman spectroscopy reveals that oxygen vacancies facilitate the preferential formation ofγ-CoOOH overβ-CoOOH during electrocatalysis,thereby promoting the generation of the active CoO_(2)phase.Combining in situ infrared spectroscopy with density functional theory(DFT)calculations,we unambiguously establish the reaction pathway,which proceeds via the sequence of HMF→5-hydroxymethyl-2-fur ancarboxylic acid(HMFCA)→2-formyl-5-furancarboxylic acid(FFCA)→2,5-furandicarboxylic acid(FDCA),and reveal the pivotal role of the active CoO_(2)species in accelerating hydroxyl radical oxidation.This work not only provides fundamental mechanistic insights into oxygen vacancy-mediated catalyst design but also offers a novel strategy for developing high-performance transition metal oxide electrocatalysts for biomass valorization.
基金supported by the National Natural Science Foundation of China(22278021)State Key Laboratory of Chemical Engineering(No.SKL-ChE-23A01).
文摘Achieving high selectivity to 2,5-furandicarboxylic acid(FDCA)in the photocatalytic oxidation of 5-hydroxymethylfurfural(HMF)in aqueous solution advocates the principle of green and sustainable chemistry,but still remains a significant challenge.Herein,manipulating the reactive oxygen species(ROS)has been realized and dramatically promotes the selective photocatalytic oxidation of HMF in aqueous solution.A high FDCAyield of 98.6% has been achieved after 3 h of visible light irradiation over the as-prepared FeO_(x)-Au/TiO_(2) catalyst,being one of the leading photocatalytic performances.Furthermore,satisfactory FDCA yields of higher than 80%could be realized even in the outdoor environment under natural sunlight irradiation,regardless of sunny or cloudy weather.A combination study including physical characterization,kinetic analysis,radical trapping experiments and density functional theory calculations unveils the rate-determining step(oxidation of hydroxyl group)and respective contributions of the generated ROS(1O_(2) and·O_(2)-)in each step of the entire reaction network.The present work would push ahead the understanding of HMF photocatalytic oxidation and contribute to the rational design of high-performance photocatalysts.
基金the National Nature Science Foundation of China for Excellent Young Scientists Fund(32222058)Fundamental Research Foundation of CAF(CAFYBB2022QB001).
文摘Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.
