Synergetic enhancement of selectivity for electroreduction of CO_(2)to C_(2)H_(4)by crystal facet engineering and tandem catalysis over silver-incorporated-cuprous oxides

Electrochemical CO_(2)reduction to C_(2)H_(4)can provide a sustainable route to reduce globally accelerating CO_(2)emissions and produce energy-rich chemical feedstocks.However,the poor selectivity in C_(2)H_(4)electrosynthesis limits its implementation in industrially interesting processes.Herein,we report a composite structured catalyst composed of Ag and Cu_(2)O with different crystal faces to achieve highly efficient reduction of CO_(2)to C_(2)H_(4).The catalyst composed of Ag and octahedral Cu_(2)O enclosed with(111)facet exhibits the best CO_(2)electroreduction performance,with the Faradaic efficiency(FE)and partial current density reaching 66.8%and 17.8 mA cm2 for C_(2)H_(4)product at-1.2 VRHE in 0.5 M KHCO_(3),respectively.Physical characterization and electrochemical test analysis indicate that the high selectivity for C_(2)H_(4)product stems from the synergistic effect of crystal faces control engineering and tandem catalysis.Specifically,Ag can provide optimal availability of CO intermediate by suppressing hydrogen evolution;subsequently,C-C coupling is promoted on the intimate surface of Cu_(2)O with facetdependent selectivity.The insights gained from this work may be beneficial for designing efficient multicomponent catalysts for improving the selectivity of electrochemical CO_(2)reduction reaction to generate C2þproducts.

Atomic-scale tuned interface of nickel-rich cathode for enhanced electrochemical performance in lithium-ion batteries

The Ni-rich layered LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)(NMC622)is one promising cathode for lithium-ion batteries(LIBs),but suffers from poor cycling stability under high cutoff potentials.The performance degradation was reflected as capacity fading and voltage drop,having their roots in instable interface of NMC622.Aimed at improving interfacial stability,in this study,we deposited nanoscale ZrO_(2) coatings conformally over NMC622 cathodes using atomic layer deposition(ALD).We found that,under a high cutoff voltage(4.5 V),the ALD ZrO_(2) coatings evidently improved the performance of NMC622 cathode,showing better cyclability and higher sustainable capacity.In addition,the ALD coatings dramatically boosted the rate capability of NMC622.All these compelling performance results are ascribed to the atomic-scale tunable ZrO_(2) coatings via ALD,which create stable interface and thereby inhibit unfavorable evolutions.In the study,we utilize a suite of characterization tools and various analyses to clarify the effects of ALD ZrO_(2) coatings.This study will be helpful for improving the performance of nickel-rich cathodes via interfacial engineering using ALD.