Fe3+-Mediated Pt/Y Zeolite Catalysts Display Enhanced Metal-Bronsted Acid Interaction and Synergistic Cascade Hydrogenolysis Reactions

Strong metal-Bronsted acid interaction is critical for interfacial catalysis. Tunable electronic coupling at the metal/acid interface for tandem C-H and C-O bond activation has been largely unexplored. We reported a simple design principle for Pt-Fe3+ interfacial catalysts to tailor the electron structure between metallic and structural acidic frameworks via the strong Pt-Bronsted acid interaction, for cascade hydrogenolysis of glycerol involving tandem C-H and C-O cleavage. One of the key findings in this work is that the formation of Fe(OH)O species in Pt-Fe3+ hybrids contributes to the enhanced surface Bronsted acidity and weakened Pt-H binding strength. Thus, the proposed Pt-Bronsted acid catalysts show synergistic performances for cascade hydrogenolysis of glycerol, with a 3-fold activity (turnover frequency (TOF) = 455.2 h(-1)) and enhanced selectivity toward ethylene glycol and propylene glycol (combined selectivity of similar to 70%), compared to monometallic Pt/Y-IM catalysts (TOF = 106.3 h(-1), selectivity = 16.2%). In addition, the size-sensitivity studies on Pt-Fe3+ catalysts with Pt particle sizes ranging from 1.8 nm to 3.8 nm showed that catalytic C-H and C-O bond cleavage possibly follow sigma(-) and pi-bond activation mechanisms, respectively. The simple strategy discussed in this work for synthesizing metal-acid catalysts provides new insights into rational design of effective catalysts for cascade hydrogenolysis of various other bioderived oxygenates to value-added products.