CO2 Activation on Ni(111) and Ni(110) Surfaces in the Presence of Hydrogen.
CO2 Activation on Ni(111) and Ni(110) Surfaces in the Presence of Hydrogen.
复制标题
DOI：
10.1021/acs.jpclett.3c00790
复制
发表时间：
2023-05
期刊：
影响因子：
--
通讯作者：
Y. Zang;Jun Cai;Yong Han;Huanyang Wu;Weihu Zhu;Shucheng Shi;Hui Zhang;Yihua Ran;Fan Yang;M. Ye;Bo Yang;Yimin Li;Z. G. Liu
中科院分区：
文献类型：
--
作者：
Y. Zang;Jun Cai;Yong Han;Huanyang Wu;Weihu Zhu;Shucheng Shi;Hui Zhang;Yihua Ran;Fan Yang;M. Ye;Bo Yang;Yimin Li;Z. G. Liu
用常压X射线光电子能谱（APXPS）在Ni（111）和Ni（110）表面上研究了H_2存在下CO_2活化的结构敏感性。基于APXPS结果和计算机模拟，我们认为，在室温附近，Ni（111）表面上CO2的氢助活化是主要的反应途径，而Ni（110）表面上CO2的氧化还原途径占主导地位。随着温度的升高，两种活化途径被平行激活。当Ni（111）表面在升高的温度下被完全还原为金属态时，可以在Ni（110）上观察到两种稳定的Ni氧化物物种。转换频率的测量表明，Ni（110）上的低配位中心促进CO2加氢制甲烷的活性和选择性。我们的研究结果提供了深入了解的作用，低配位的Ni网站在纳米粒子催化剂的CO2甲烷化。
The structure sensitivity of CO2 activation in the presence of H2 has been identified by ambient-pressure X-ray photoelectron spectroscopy (APXPS) on Ni(111) and Ni(110) surfaces under identical reaction conditions. Based on the APXPS results and computer simulations, we propose that, around room temperature, the hydrogen-assisted activation of CO2 is the major reaction path on Ni(111), while the redox pathway of CO2 prevails on Ni(110). With increasing temperature, the two activation pathways are activated in parallel. While the Ni(111) surface is fully reduced to the metallic state at elevated temperatures, two stable Ni oxide species can be observed on Ni(110). Turnover frequency measurements indicate that the low-coordinated sites on Ni(110) promote the activity and selectivity of CO2 hydrogenation to methane. Our findings provide insights into the role of low-coordinated Ni sites in nanoparticle catalysts for CO2 methanation.