物理化学学报2021，Vol.37Issue(5)：193-200,8.DOI:10.3866/PKU.WHXB202009023
CeO2担载Cu纳米粒子电催化CO2还原产乙烯:CeO2不同暴露晶面对催化性能的影响
Electrocatalytic CO2 Reduction to Ethylene over CeO2-Supported Cu Nanoparticles:Effect of Exposed Facets of CeO2
摘要
Abstract
Fossil fuels are expected to be the major source of energy for the next few decades.However,combustion of nonrenewable resources leads to the release of large quantities of CO2,the primary greenhouse gas.Notably,the concentration of CO2 in the atmosphere is increasing annually at an astounding rate.Electrochemical CO2 reduction(ECR)to value-added fuels and chemicals using electricity from intermittent renewable energy sources is a carbon-neutral method to alleviate anthropogenic CO2 emissions.Despite the steady progress in the selective generation of C1 products(CO and formic acid),the production of multi-carbon species still suffers from low selectivity and efficiency.As an ECR product,ethylene(C2H4)has a higher energy density than do C1 species and is an important industrial feedstock in high demand.However,the conversion of CO2 to C2H4 is plagued by low productivity and large overpotential,in addition to the severe competing hydrogen evolution reaction(HER)during the ECR.To address these issues,the design and development of advanced electrocatalysts are critical.Here,we demonstrate fine-tuning of ECR to C2H4 by taking advantage of the prominent interaction of Cu with shape-controlled CeO2 nanocrystals,that is,cubes,rods,and octahedra predominantly covered with(100),(110),and(111)surfaces,respectively.We found that the selectivity and activity of the ECR depended strongly on the exposed crystal facets of CeO2.The overall ECR Faradaic efficiency(FE)over Cu/CeO2(110)(FE≈56.7％)surpassed that of both Cu/CeO2(100)(FE ≈ 51.5％)and Cu/CeO2(111)(FE ≈48.4％)in 0.1 mol·L-1 KHCO3 solutions with an H-type cell.This was in stark contrast to the exclusive occurrence of the HER over pure carbon paper,CeO2(100),CeO2(110),and CeO2(111).In particular,the FE toward C2H4 formation and the partial current density increased in the sequence Cu/CeO2(111)＜Cu/CeO2(100)＜Cu/CeO2(110)within applied bias potentials from-1.00 to-1.15 V(vs.the reversible hydrogen electrode),reaching 39.1％over Cu/CeO2(110)at a mild overpotential(1.13 V).The corresponding values for Cu/CeO2(100)and Cu/CeO2(111)were FEc2H4 ≈ 31.8％and FEc2H4 ≈29.6％,respectively.The C2H4 selectivity was comparable to that of many reported Cu-based electrocatalysts at similar overpotentials.Furthermore,the FE for C2H4 remained stable even after 6 h of continuous electrolysis.The superior ECR activity of Cu/CeO2(110)to yield C2H4 was attributed to the metastable(110)surface,which not only promoted the effective adsorption of CO2 but also remarkably stabilized Cu+,thereby boosting the ECR to produce C2H4.This work offers an alternative strategy to enhance the ECR efficiency by crystal facet engineering.关键词
二氧化碳/电化学还原/乙烯/铜/二氧化铈/暴露晶面Key words
CO2/Electrochemical reduction/Ethylene/Cu/CeO2/Exposed facet分类
化学化工引用本文复制引用
楚森林,李欣,Alex W.Robertson,孙振宇..CeO2担载Cu纳米粒子电催化CO2还原产乙烯:CeO2不同暴露晶面对催化性能的影响[J].物理化学学报,2021,37(5):193-200,8.基金项目
This work was supported by National Natural Science Foundation of China(21972010)and Beijing Natural Science Foundation,China(2192039).国家自然科学基金(21972010)与北京自然科学基金(2192039)资助项目 （21972010）
