Zr-Doped NiO Nanoparticles for Low-Temperature Methane Combustion

The development of efficient and stable non-noble metal-based catalysts for low-temperature methane combustion is extremely important and still a profound challenge. Herein, high-performance Ni1–xZrxO2−δ solid solution nanocatalysts were prepared through a homogeneous co-precipitation strategy, where the hydrolysis of CO32– was controlled to facilitate the dispersion and interaction of Ni and Zr components. The structural and surface properties of nanocatalysts were facilely tuned by modulating the Zr doping content. An optimized incorporation of Zr into the NiO lattice endowed the Ni0.89Zr0.11O2−δ nanocatalyst with a small crystallite size, large specific surface area, and simultaneously increased surface acidic–basic sites. Moreover, abundant active Ni2+ and surface oxygen species were generated due to the promoted conversion of Ni3+ to Ni2+, which played pivotal roles in the adsorption/activation of methane and further oxidation of reaction intermediates to CO2. Consequently, Ni0.89Zr0.11O2−δ exhibited an excellent low-temperature activity, high CO2 selectivity, and superior catalytic stability under both dry and wet conditions.