In Situ Exsolution of High-Density Ni Nanoparticles in LaAl <sub>0.3</sub> Mn <sub>0.2</sub> Ni <sub>0.5</sub> O <sub>3−δ</sub> Cathode for the Electro-Thermocatalytic CO <sub>2</sub> -Intensified Dry Reforming of Methane
Haolin Liu, Shuo Wang, Houfu Lv, Rongtan Li, Yuxiang Shen, Chaobin Zeng, Xiaomin Zhang, Yuefeng Song, Na Ta, Shaowei Zhang, Fang Lü, Guoxiong Wang, Xinhe Bao
Abstract
The tandem electro-thermocatalytic system, which integrates dry reforming of methane with reverse water–gas shift and H 2 O electrolysis reactions within a solid oxide electrolysis cell, offers an innovative path for the utilization of CO 2 -rich feedstocks. The identification of the correlation between the interface-dependent characteristics and both catalytic activity and stability remains a formidable challenge. Herein, we focus on the exsolution of high-density and well-dispersed nanoparticles semiembedded on the LaAl 0.3 Mn 0.2 Ni 0.5 O 3−δ cathode by modulating the Al and Mn co-doping strategy. The substantial and stable metal@perovskite interfacial sites exhibit high intrinsic activity for the tandem electro-thermocatalytic system, which provides high single-pass CO 2 and CH 4 conversion over 92%, syngas yield over 93%, apparent CH 4 reducibility up to 3.91, and a CH 4 turnover frequency of 73.77 mol CH4 mol Ni –1 s –1 using various CO 2 -rich feedstocks (CO 2 /CH 4 = 2–4) at 800 °C. In situ electrochemical diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculations demonstrate the crucial role of *OH electrolysis in the tandem catalysis process. This work elucidates the structure–activity relationship between the metal@support interfacial sites and catalytic activity and stability for the tandem electro-thermocatalytic system.