Turning on Low-Temperature Catalytic Conversion of Biomass Derivatives through Teaming Pd₁ and Mo₁ Single-Atom Sites

On-purpose atomic scale design of catalytic sites, specifically active and selective at low temperature for a target reaction, is a key challenge. Here, we report teamed Pd₁ and Mo₁ single-atom sites that exhibit high activity and selectivity for anisole hydrodeoxygenation to benzene at low temperatures, 100-150 °C, where a Pd metal nanoparticle catalyst or a MoO₃ nanoparticle catalyst is individually inactive. The catalysts built from Pd₁ or Mo₁ single-atom sites alone are much less effective, although the catalyst with Pd₁ sites shows some activity but low selectivity. Similarly, less dispersed nanoparticle catalysts are much less effective. Computational studies show that the Pd₁ and Mo₁ single-atom sites activate H₂ and anisole, respectively, and their combination triggers the hydrodeoxygenation of anisole in this low-temperature range. The Co₃O₄ support is inactive for anisole hydrodeoxygenation by itself but participates in the chemistry by transferring H atoms from Pd₁ to the Mo₁ site. This finding opens an avenue for designing catalysts active for a target reaction channel such as conversion of biomass derivatives at a low temperature where neither metal nor oxide nanoparticles are.