Collateral hydrogenation over proton-conducting Ni/BaZr 0.85 Y 0.15 O 3- δ catalysts for promoting CO 2 methanation.

Despite the importance of CO 2 methanation for eco-friendly carbon-neutral fuel recycling, the current technologies, relying on catalytic hydrogenation over metal-based catalysts, face technological and economical limitations. Herein, we employ the steam hydrogenation capability of proton conductors to achieve collateral CO 2 methanation over the Ni/BaZr 0.85 Y 0.15 O 3- δ catalyst, which is shown to outperform its conventional Ni/Al 2 O 3 counterpart in terms of CH 4 yield (8% higher) and long-term stability (3% higher for 150 h) at 400 °C while exhibiting a CH 4 selectivity above 98%. Moreover, infrared and X-ray photoelectron spectroscopy analyses reveal the appearance of distinct mobile proton-related OH bands during the methanation reaction.