In recent years, the scale of use of fuel cells (FCs) has been increasing continuously. One of the essential elements that affect their work is a catalyst. Precious metals (mainly platinum) are known for their hig...In recent years, the scale of use of fuel cells (FCs) has been increasing continuously. One of the essential elements that affect their work is a catalyst. Precious metals (mainly platinum) are known for their high efficiency as FC catalysts. However, their high cost holds back the FCs from application on a large scale. Therefore, catalysts that do not contain precious metals are sought. Studies are focused mainly on the search for fuel electrode catalysts, but for the efficiency of FCs also the oxygen electrode catalyst is of great significance. The paper presents an analysis of the possibilitiesof using Ni-Co alloy as a catalyst for the oxygen electrode of the FC.展开更多
Electrocatalytic hydrogenation(ECH)enables the sustainable production of chemicals under ambient condition;however,suffers from serious competition with hydrogen(H2)evolution and the use of precious metals as electroc...Electrocatalytic hydrogenation(ECH)enables the sustainable production of chemicals under ambient condition;however,suffers from serious competition with hydrogen(H2)evolution and the use of precious metals as electrocatalysts.Herein,molybdenum disulfide is for the first time developed as an efficient and noble-metal-free catalyst for ECH via in situ intercalation of ammonia or alkyl-amine cations.This interlayer engineering regulates phase transition(2H→1 T),and effectively ameliorates electronic configurations and surface hydrophobicity to promote the ECH of biomass-derived oxygenates,while prohibiting H2 evolution.The optimal one intercalated by dimethylamine(MoS_(2)-DMA)is capable of hydrogenating furfural(FAL)to furfuryl alcohol with high Faradaic efficiency of 86.3%–73.3%and outstanding selectivity of>95.0%at−0.25 to−0.65 V(vs.RHE),outperforming MoS_(2) and other conventional metals.Such prominent performance stems from the enhanced chemisorption and surface hydrophobicity.The chemisorption of H intermediate and FAL,synchronously strengthened on the edge-sites of MoS_(2)-DMA,accelerates the surface elementary step following Langmuir-Hinshelwood mechanism.Moreover,the improved hydrophobicity benefits FAL affinity to overcome diffusion limitation.Discovering the effective modulation of MoS_(2) from a typical H2 evolution electrocatalyst to a promising candidate for ECH,this study broadens the scope to exploit catalysts used for electrochemical synthesis.展开更多
文摘In recent years, the scale of use of fuel cells (FCs) has been increasing continuously. One of the essential elements that affect their work is a catalyst. Precious metals (mainly platinum) are known for their high efficiency as FC catalysts. However, their high cost holds back the FCs from application on a large scale. Therefore, catalysts that do not contain precious metals are sought. Studies are focused mainly on the search for fuel electrode catalysts, but for the efficiency of FCs also the oxygen electrode catalyst is of great significance. The paper presents an analysis of the possibilitiesof using Ni-Co alloy as a catalyst for the oxygen electrode of the FC.
基金supported by the National Key Research and Development Program of China (2018YFA0209402)the National Natural Science Foundation of China (21773093)
文摘Electrocatalytic hydrogenation(ECH)enables the sustainable production of chemicals under ambient condition;however,suffers from serious competition with hydrogen(H2)evolution and the use of precious metals as electrocatalysts.Herein,molybdenum disulfide is for the first time developed as an efficient and noble-metal-free catalyst for ECH via in situ intercalation of ammonia or alkyl-amine cations.This interlayer engineering regulates phase transition(2H→1 T),and effectively ameliorates electronic configurations and surface hydrophobicity to promote the ECH of biomass-derived oxygenates,while prohibiting H2 evolution.The optimal one intercalated by dimethylamine(MoS_(2)-DMA)is capable of hydrogenating furfural(FAL)to furfuryl alcohol with high Faradaic efficiency of 86.3%–73.3%and outstanding selectivity of>95.0%at−0.25 to−0.65 V(vs.RHE),outperforming MoS_(2) and other conventional metals.Such prominent performance stems from the enhanced chemisorption and surface hydrophobicity.The chemisorption of H intermediate and FAL,synchronously strengthened on the edge-sites of MoS_(2)-DMA,accelerates the surface elementary step following Langmuir-Hinshelwood mechanism.Moreover,the improved hydrophobicity benefits FAL affinity to overcome diffusion limitation.Discovering the effective modulation of MoS_(2) from a typical H2 evolution electrocatalyst to a promising candidate for ECH,this study broadens the scope to exploit catalysts used for electrochemical synthesis.