<scp>Low‐temperature</scp> total oxidation of methane by pore‐ and vacancy‐engineered <scp>NiO</scp> catalysts

Abstract

Abstract Designing methane combustion catalysts operated under low temperature (&lt;400°C) remains a huge challenge, especially for noble‐metal–free catalytic systems. With NaCl as a crystalline scaffold, NiO catalyst with abundant oxygen vacancies and an ultra‐high–specific surface area of 181 m 2 g −1 is obtained. The mesoporous NiO exhibits outstanding CH 4 combustion performance ( T 90 = 370°C at the weight hourly space velocity (WHSV) = 20,000 mL g −1 h −1 ). X‐ray photoelectron spectroscopy (XPS), H 2 ‐temperature‐programmed reduction (TPR), kinetic measurements, and O 18 isotope‐labeling experiments together disclose the key role of surface lattice oxygen and reaction mechanism by NiO catalysts. More importantly, the excellent stability of NiO by doping La was obtained (low‐temperature thermal stability: 385°C, 400 h, 4 vol% H 2 O).