Solar-enhanced CO₂ conversion with CH₄ over synergetic NiCo alloy catalysts with light-to-fuel efficiency of 33.8%

Conversion of CO₂ into useful chemical feedstocks or fuels using solar energy is a promising technology to tackle both climate change and energy shortage challenges. Here, NiCo alloys derived from AlMg hydrotalcite are introduced for photothermal synergetic CO₂ conversion with CH₄ with an ultrahigh light-to-fuel efficiency of 33.8% and a low carbon deposition rate of 0.011 g_c g⁻¹_cat h⁻¹. The ultrahigh efficiency is attributed to the high solar absorptance of NiCo alloys, unique synergistic catalysis of NiCo active sites, and the photo-enhanced reactant activation. Inhibition of carbon formation lies in concurrent reduced energy barriers of CH* oxidation to CHO* and increased energy barriers of CH* dissociation to C*, enabled by the unique synergistic catalysis of NiCo alloys. Direct light illumination results in an obvious decrease of the apparent activation energy of CO₂ conversion with CH₄, making light-driven CO₂ conversion superior to conventional thermal-driven techniques. Herein, a new platform for achieving efficient solar-driven CO₂ conversion with ultrahigh light-to-fuel efficiency based on NiCo alloy catalyst is provided and the way for sclable deployment of photothermal CO₂-to-fuel techniques is paved.