Green CO2-Assisted Synthesis of Mono- and Bimetallic Pd/Pt Nanoparticles on Porous Carbon Fabricated from Sorghum for Highly Selective Hydrogenation of Furfural

The green utilization of biomass waste and its ecofriendly conversion into biofuels and value-added chemicals play a crucial role in resolving energy demand and environmental pollution. Herein, we report a win-win strategy to utilize biomass waste to fabricate functional materials and then transform biomass-derived source into valuable products. We developed a one-step strategy using the green solvent CO2 deposition method to spatially confine monometallic Pd and Pt and bimetallic Pd-Pt nanoparticles in a porous carbon fabricated from biomass waste sorghum at a very low temperature of 40-70 degrees C. The synthesized monometallic Pd and Pt and bimetallic Pd-Pt nanoparticles display superior performance in the selective conversion of biomass-based furfural into fine chemicals, furfuryl alcohol and tetrahydrofurfuryl alcohol. With only 3 wt % Pd or 3 wt % Pt supported on the synthesized porous carbon, these catalysts are far superior to the commercial 5 wt % Pd or Pt on carbon support, respectively. The turnover number of the as prepared 3 wt % Pd/C catalyst shows similar to 7 times improvement compared with the commercial 5 wt % Pd/C. This study provided a one-step method to precisely confine monometallic Pd and Pt and bimetallic Pd-Pt in the porous channel of the carbon support, offered more catalytic active sites, and presented excellent performance and high stability. The methodology developed in this work is promising for the synthesis of various metallic nanoparticles and valorization of biomass.