H2 Reduction-Mediated Reaction Pathway Switching in Bimetallic Pt–WOx Catalysts: Shifting Fatty Acid Deoxygenation from Decarboxylation to Decarbonylation

The decarbonylation of fatty acids represents a promising route for producing value-added alkenes; however, the thermodynamic preference for decarboxylation over decarbonylation poses a fundamental challenge. Herein, we developed a hydrogen-reducible PtWO x /SiO 2 bimetallic catalyst that enables pathway switching from predominant decarboxylation to selective decarbonylation. The PtWO x /SiO 2 –Air catalyst calcined in air exhibited outstanding fatty acid decarboxylation performance, achieving 99% stearic acid conversion and 85% heptadecane selectivity. In contrast, the hydrogen-reduced PtWO x /SiO 2 –H 2 catalyst shifted the deoxygenation pathway of stearic acid from decarboxylation to decarbonylation, increasing the selectivity for heptadecene from 5.9 to 57.1%. Structural characterization revealed that Pt nanoparticles were surrounded by amorphous WO x domains, creating abundant Pt–WO x interfaces that strengthened fatty acid adsorption. X-ray photoelectron spectroscopy (XPS) and CO–DRIFTS showed that hydrogen reduction converted PtO 2 /WO x to Pt/WO x, while presenting a strong metal–support interaction (SMSI) between Pt and WO x, inducing electron transfer from Pt to W and generating Pt δ+ . These Pt δ+ sites weakened the d-2π* back-donation effect and lowered the CO adsorption energy, thereby promoting decarbonylation. Density functional theory (DFT) calculations further confirmed that the higher binding energy barriers for C 3 H 7 * and H* in Pt/WO x, along with the lower desorption energy barriers for CO, favored the decarbonylation pathway. This work provides a catalyst design strategy with electronic modulation to overcome the thermodynamic limitations of fatty acid decarbonylation.