ungsten carbides have attracted wide attentions as Pt substitute electrocatalysts for hydrogen evolution reaction (HER), due to their good stability in an acid environment and Pt-like behaviour in hydrolysis. However,...ungsten carbides have attracted wide attentions as Pt substitute electrocatalysts for hydrogen evolution reaction (HER), due to their good stability in an acid environment and Pt-like behaviour in hydrolysis. However, quantum chemistry calculations predict that the strong tungsten-hydrogen bonding hinders hydrogen desorption and restricts the overall catalytic activity. Synergistic modulation of host and guest electronic interaction can change the local work function of a compound, and therefore, improve its electrocatalytic activity over either of the elements individually. Herein, we develop a creative and facile solid-state approach to synthesize self-supported carbon-encapsulated single-phase WC hybrid nanowires arrays (nanoarrays) as HER catalyst. The theoretical calculations reveal that carbon encapsulation modifies the Gibbs free energy of H* values for the WC adsorption sites, endowing a more favorable C@WC active site for HER. The experimental results exhibit that the hybrid WC nanoarrays possess remarkable Pt-like catalytic behavior, with superior activity and stability in an acidic media, which can be compared to the best non-noble metal catalysts reported to date for hydrogen evolution reaction. The present results and the facile synthesis method open up an exciting avenue for developing cost-effective catalysts with controllable morphology and functionality for scalable hydrogen generation and other carbide nanomaterials applicable to a range of electrocatalytic reactions.展开更多
The electroreduction of CO_(2)(CO_(2)RR)into value-added chemicals is a sustainable strategy for mitigating global warming and managing the global carbon balance.However,developing an efficient and selective catalyst ...The electroreduction of CO_(2)(CO_(2)RR)into value-added chemicals is a sustainable strategy for mitigating global warming and managing the global carbon balance.However,developing an efficient and selective catalyst is still the central challenge.Here,we developed a simple two-step pyrolysis method to confine low-valent Ni-based nanoparticles within nitrogen-doped carbon(Ni-NC).As a result,such Ni-based nanoparticles can effectively reduce CO_(2)to CO,with a maximum CO Faradaic efficiency(FE)of 98%at an overpotential of 0.8 V,as long as good stability.Experimental and the density functional theory(DFT)calculation results reveal that low-valent Ni plays a key role in activity and selectivity enhancement.This study presents a new understanding of Ni-based CO_(2)RR,and provides a simple,scalable approach to the synthesis of low-valent catalysts towards efficient CO_(2)RR.展开更多
基金This work was supported by the Shenzhen Science and Technology Research Grant(ZDSYS201707281026184)the Natural Science Foundation of Shenzhen(JCYJ20190813110605381).
文摘ungsten carbides have attracted wide attentions as Pt substitute electrocatalysts for hydrogen evolution reaction (HER), due to their good stability in an acid environment and Pt-like behaviour in hydrolysis. However, quantum chemistry calculations predict that the strong tungsten-hydrogen bonding hinders hydrogen desorption and restricts the overall catalytic activity. Synergistic modulation of host and guest electronic interaction can change the local work function of a compound, and therefore, improve its electrocatalytic activity over either of the elements individually. Herein, we develop a creative and facile solid-state approach to synthesize self-supported carbon-encapsulated single-phase WC hybrid nanowires arrays (nanoarrays) as HER catalyst. The theoretical calculations reveal that carbon encapsulation modifies the Gibbs free energy of H* values for the WC adsorption sites, endowing a more favorable C@WC active site for HER. The experimental results exhibit that the hybrid WC nanoarrays possess remarkable Pt-like catalytic behavior, with superior activity and stability in an acidic media, which can be compared to the best non-noble metal catalysts reported to date for hydrogen evolution reaction. The present results and the facile synthesis method open up an exciting avenue for developing cost-effective catalysts with controllable morphology and functionality for scalable hydrogen generation and other carbide nanomaterials applicable to a range of electrocatalytic reactions.
基金the financial support from the Shenzhen Science and Technology Research Grant(No.JCYJ20200109140416788,China)the Chemistry and Chemical Engineering Guangdong Laboratory(No.1922018,China)National Key R&D Program of China(No.2020YFB0704500)。
文摘The electroreduction of CO_(2)(CO_(2)RR)into value-added chemicals is a sustainable strategy for mitigating global warming and managing the global carbon balance.However,developing an efficient and selective catalyst is still the central challenge.Here,we developed a simple two-step pyrolysis method to confine low-valent Ni-based nanoparticles within nitrogen-doped carbon(Ni-NC).As a result,such Ni-based nanoparticles can effectively reduce CO_(2)to CO,with a maximum CO Faradaic efficiency(FE)of 98%at an overpotential of 0.8 V,as long as good stability.Experimental and the density functional theory(DFT)calculation results reveal that low-valent Ni plays a key role in activity and selectivity enhancement.This study presents a new understanding of Ni-based CO_(2)RR,and provides a simple,scalable approach to the synthesis of low-valent catalysts towards efficient CO_(2)RR.
