摘要
Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles （NPs） in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered the development of efficient catalysts for CO2 electroreduction. Herein, we report the systematic engineering of active phases of Pd NPs, which are exploited to select reaction pathways for CO2 electroreduction. In situ X-ray absorption spectroscopy, in situ attenuated total reflection-infrared spectroscopy, and density functional theory calculations suggest that the formation of a hydrogen-adsorbed Pd surface on a mixture of the α- and β-phases of a palladium-hydride core （α＋β PdHx@PdHx） above -0.2 V （vs. a reversible hydrogen electrode） facilitates formate production via the HCOO intermediate, whereas the formation of a metallic Pd surface on the β-phase Pd hydride core （β PdHx@Pd） below -0.5 V promotes CO production via the COOH＂ intermediate. The main product, which is either formate or CO, can be selectively produced with high Faradaic efficiencies （〉90%） and mass activities in the potential window of 0.05 to -0.9 V with scalable application demonstration.
Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles （NPs） in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered the development of efficient catalysts for CO2 electroreduction. Herein, we report the systematic engineering of active phases of Pd NPs, which are exploited to select reaction pathways for CO2 electroreduction. In situ X-ray absorption spectroscopy, in situ attenuated total reflection-infrared spectroscopy, and density functional theory calculations suggest that the formation of a hydrogen-adsorbed Pd surface on a mixture of the α- and β-phases of a palladium-hydride core （α＋β PdHx@PdHx） above -0.2 V （vs. a reversible hydrogen electrode） facilitates formate production via the HCOO intermediate, whereas the formation of a metallic Pd surface on the β-phase Pd hydride core （β PdHx@Pd） below -0.5 V promotes CO production via the COOH＂ intermediate. The main product, which is either formate or CO, can be selectively produced with high Faradaic efficiencies （〉90%） and mass activities in the potential window of 0.05 to -0.9 V with scalable application demonstration.
作者简介
These authors contributed equally to this work.These authors contributed equally to this work.These authors contributed equally to this work.Address correspondence to Jianguo Wang, jgw@zjut.edu.cnAddress correspondence to Guoxiong Wang, wanggx@dicp.ac.cnAddress correspondence to Xinhe Bao, xhbao@dicp.ac.cn
