Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to ethylene(C_(2)H_(4))represents a promising approach to reducing CO_(2)emissions and producing high-value chemicals.The ethylene productivity is always limited by t...Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to ethylene(C_(2)H_(4))represents a promising approach to reducing CO_(2)emissions and producing high-value chemicals.The ethylene productivity is always limited by the slow reaction kinetics and the high-performance catalysts are significantly desired.Many efforts have been made to develop a catalyst to activate CO_(2)molecules.However,as another reactant,H2O activation does not receive the attention it deserves.In particular,slow H2O dissociation kinetics limit the rate of proton supply,severely impairing the production of C_(2)H_(4).Here,we designed a MgO-modified CuO catalyst(MgO/CuO),which can promote H2O dissociation and enhance CO_(2)adsorption at the same time to realize the efficient ethylene production.The optimal catalyst exhibits a Faraday efficiency for C_(2)H_(4)reached 54.4%at−1.4 V vs.RHE in an H-cell,which is 1.4 times that of pure CuO(37.9%),and it was further enhanced to a 56.7%in a flow cell,with a high current density of up to 535.9 mA cm−2 at−1.0 V vs.RHE.Experimental and theoretical calculations show that MgO/CuO plays a bifunctional role in the CO_(2)RR,which facilitates the adsorption and activation of CO_(2)by CuO and simultaneously accelerates H2O dissociation by MgO doping.The in situ XRD experiments demonstrate that the introduction of MgO protects CuO active phase to avoid overreduction and preserves the active centers for CO_(2)RR.In combination with in situ FTIR and DFT calculations,the protonation process from*CO to*COH and asymmetric C–C coupling step are promoted by the enhanced water activation and proton coupling on MgO/CuO.This work provides new insights into the CO_(2)and H_(2)O coactivation mechanism in CO_(2)RR and a potential universal strategy to design ethylene production electrocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U21B2099,U22A20425,and 22208377)Natural Science Foundation of Shandong Province(ZR2021QE062)Fundamental Research Funds for the Central Universities,Ocean University of China(grant number 202364004)。
文摘Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to ethylene(C_(2)H_(4))represents a promising approach to reducing CO_(2)emissions and producing high-value chemicals.The ethylene productivity is always limited by the slow reaction kinetics and the high-performance catalysts are significantly desired.Many efforts have been made to develop a catalyst to activate CO_(2)molecules.However,as another reactant,H2O activation does not receive the attention it deserves.In particular,slow H2O dissociation kinetics limit the rate of proton supply,severely impairing the production of C_(2)H_(4).Here,we designed a MgO-modified CuO catalyst(MgO/CuO),which can promote H2O dissociation and enhance CO_(2)adsorption at the same time to realize the efficient ethylene production.The optimal catalyst exhibits a Faraday efficiency for C_(2)H_(4)reached 54.4%at−1.4 V vs.RHE in an H-cell,which is 1.4 times that of pure CuO(37.9%),and it was further enhanced to a 56.7%in a flow cell,with a high current density of up to 535.9 mA cm−2 at−1.0 V vs.RHE.Experimental and theoretical calculations show that MgO/CuO plays a bifunctional role in the CO_(2)RR,which facilitates the adsorption and activation of CO_(2)by CuO and simultaneously accelerates H2O dissociation by MgO doping.The in situ XRD experiments demonstrate that the introduction of MgO protects CuO active phase to avoid overreduction and preserves the active centers for CO_(2)RR.In combination with in situ FTIR and DFT calculations,the protonation process from*CO to*COH and asymmetric C–C coupling step are promoted by the enhanced water activation and proton coupling on MgO/CuO.This work provides new insights into the CO_(2)and H_(2)O coactivation mechanism in CO_(2)RR and a potential universal strategy to design ethylene production electrocatalysts.
