Understanding catalytic active-sites threshold of supported Pt catalysts for selective hydrogenation of phenol as a model compound for future biofuels

Catalytic transformation of bio-derived compounds to value-added chemicals and liquid fuels plays a significant role in biomass utilization and essentially depends on catalyst design. The active-sites threshold over Pt/Ti 3 Al x C 2 T y catalysts in selective hydrogenations (e.g., phenol and furfural) were identified, and XRD, TEM, XPS and FT-IR were conducted to analyze crystal structures, morphologies, chemical states, and adsorptive properties. The catalytic results of phenol hydrogenation demonstrated that the catalysts completely lost activity when Pt loading was 0.25 %wt. FT-IR analyses of phenol-adsorbed catalysts and supports showed that the threshold resulted from the massive adsorption of phenol molecules that occupied Pt active sites, suppressing H 2 adsorption. By addition of Au nanoparticles, the phenol hydrogenation occurred over bimetallic Au 0.8 -Pt 0.2 /Ti 3 Al x C 2 T y , whereas merely Au nanoparticles were inactive for phenol hydrogenation. The findings could inspire peer researchers to design supported metal catalysts and regulate adsorption or interaction between catalyst surfaces and reactants.