PtCo Nanoporous Foam as Catalyst for Selective Hydrogenolysis Reactions

Bimetallic catalysts consisting of a late transition metal, such as Pt, together with an oxophilic metal, such as Co, have the potential to selectivity activate the desired transformation of biomass-derived molecules to fuels. The unique electronic and chemical properties of bimetallic catalysts, which are different from that of their origin metallic elements, can be adjust, leading to high catalytic selectivity that cannot be attained with single metals.

In this work, high surface area nanoporous Pt-Co alloy was prepared by low-temperature reduction (150-300^oC) of a bimetallic [Co(NH₅)Cl][PtCl₄] salt, in which the two different metal atoms are distributed in a 1:1 ratio in each cell unit. Salt reduction led to evaporation of the inorganic ligands, reduction of the metal ions and collapse of the salt structure inducing the formation of Pt-Co nanoporous foams. The catalytic reactivity of the Pt-Co alloy toward hydrogenolysis of 5-hydroxymethylfurfural (HMF), a biomass-derived molecule, into 2,5-dimethylfuran (DMF), which is a potential liquid fuel resource, was tested. Pt-Co nanoporous foams catalyst shown a temperature-dependent structure and surface area, which affected their catalytic reactivity-selectivity properties. It was found that maximum yield of DMF reached 83.2% with a 100% conversion of HMF, over bimetallic Pt-Co catalysts that reduced at 170 ^oC, due to its novel catalyst structure.

Our work paves the way to a deeper understanding of composition-reactivity-selectivity correlations in Pt-Co as a model for bimetallic nanostructures catalysts.