Synergistic MoO_x interface engineering on Pt/CeO₂ nanorods for efficient conversion of Enteromorpha prolifera to...

The catalytic conversion of Enteromorpha prolifera derived rhamnose into 1,2-propanediol (1,2-PDO) is a promising route for valorizing marine waste. Herein, we used interface engineering to modify Pt/CeO₂ nanorods with metal oxide promoters (Mo, Sn, W), which markedly boosted the catalytic performance on 1,2-PDO formation. The Mo-modified Pt catalyst (Pt₁Mo₅/CeO₂) delivered a 58.8C-mol% yield of 1,2-PDO with a productivity of 66.3 mol_{1,2-propanediol}mol_Pt^-1 h^-1, to be the comparable highest yield to date. Combined experimental and DFT calculations revealed that the introduced MoO_x (predominantly MoO₃) functioned as a multifunctional promoter. Electronically, it facilitated Mo-to-Pt charge transfer, enhancing metallic Pt⁰ sites that were responsible for H₂ dissociation (energy barrier: 4.5 vs. 8.1 kcal mol^-1 for Pt⁰ and Pt²⁺, respectively), while Pt²⁺ sites adsorb the sugar substrate. Geometrically, MoO_x stabilized surface Ce³⁺ and oxygen vacancies and concurrently generated medium-strength Lewis acid sites. The MoO₃ layer orchestrated a cooperative catalytic cycle that efficiently coupled bond cleavage and hydrogenation, as evidenced by DFT: the rate-determining barriers for ring-opening (C-O cleavage), isomerization (1,2-H shift), and retro-aldol C-C cleavage were all substantially lowered upon Mo incorporation (e.g., C-C cleavage barrier decreased from 28.6 to 16.6 kcal mol^-1). This synergy drives a cascade reaction sequence-rhamnose ring-opening, isomerization, selective CC bond cleavage to lacticaldehyde and 1,3-dihydroxyaceton (DHA), followed by hydrogenation to 1,2-PDO. Our findings provide fundamental principles for designing multifunctional catalysts via metal-oxide interface engineering for marine biomass valorization.