Large-pore mesoporous RuNi-doped TiO2–Al2O3 nanocomposites for highly efficient selective CO methanation in hydrogen-rich reformate gases

•Large-pore mesoporous RuNi-doped TiO2–Al2O3 composites were synthesized.•1 vol% CO can efficiently be removed to levels of less than 50 ppm by SMET method.•MRNAT-30Ni exhibits long-term stability under realistic reaction conditions.

A series of large-pore mesoporous RuNi-doped TiO2–Al2O3 nanocomposites were prepared by a facile sol–gel method using a one-pot protocol based on evaporation-induced self-assembly. Owing to high density of active sites, an open nanoarchitecture and highly promotional efficiency by synergetic effects, the as-prepared nanocomposites demonstrated excellent catalytic properties in selective CO methanation (CO-SMET). The final concentration of CO can be reduced to less than 50 ppm with more than 50% selectivity over the MRNAT-30Ni catalyst. The working temperature window covered the typical working range of 200–250 °C in conventional upstream low-temperature shift reactors. The MRNAT-30Ni catalyst has excellent stability during 200 h time on stream with no detectable change in CO and CH4 concentrations, and CO in outlet reaches level below 20 ppm under realistic reaction conditions. This remarkable improvement of activity/selectivity and stability could lead to wide implementation of this one-pot protocol for the synthesis of large-pore mesoporous nanocomposite catalysts for the CO-SMET process.

Graphical abstractLarge-pore mesoporous RuNi-doped TiO2–Al2O3 composite catalysts were synthesized by a one-pot protocol based on evaporation-induced self-assembly. 1 vol% CO contained in hydrogen was cleaned to less than 50 ppm over MRNAT-30Ni by selective CO methanation with a working temperature window greater than 50 °C that included the typical working range (200–250 °C). The catalyst also exhibited long-term stability with CO outlet concentration below 20 ppm under realistic reaction conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide