100% selective methane conversion to C1 products over Ni/CeO2 nanorods

Abstract

Selective CH4 upgrading to C1 products and avoiding over oxidation remains a key challenge. Here, we develop a highly efficient Ni/CeO2 nanorods containing both uniformly dispersed Ni-single-site and NiOx/CeO2 heterojunction for 100 % selectively CH4 conversion to C1 products (CH3OH, HCHO, CH3OOH and HCOOH). Under optimized photocatalytic experimental conditions, a high C1 product yield of 5.6 mmol g-1h−1 was obtained with 100 % selectivity with presence of H2O2. Mechanism study showed that the Ni-single-site together with formed oxygen vacancy (Ov) facilitated CH4 adsorption and activation. The terminal O atom of adsorbed ·OOH can fill the Ov, with the remaining *OH initiating *CH3 dehydrogenation and forming *CH2OH, which further reacts with ·OH to generate the main product HCHO. During the whole photocatalytic process, the formed NiOx/CeO2 heterojunction promoted carrier separation and enhanced catalytic performance.