Facile use of coal combustion fly ash (CCFA) as Ni-Re bimetallic catalyst support for high-performance CO 2 methanation.

•Coal combustion fly ash was readily used to prepare Ni-Re bimetallic catalyst.•Its catalytic CO2 methanation activity was outstanding.•Re additive promoted the reaction both structurally and electronically.•Re additive also enhanced the catalyst anti-sintering and anti-coking ability.•A loop reaction mechanism was established based on in-situ DRIFTS results.