Title : Tunable anchoring of metal nanoparticles on hard carbon supports for kinetically superior and selective hydrogenation of olefins
The multiphasic nature of the catalysts, reactants and products continues to be a major obstacle in realizing enhanced kinetics without compromising on the selectivity and durability of heterogeneous chemical catalysts. Conventional understanding has focused on improving the accessible surface area and overcoming the diffusional restrictions with simultaneous nanoengineering of the catalytic surface in order to overcome these challenges. Herein, we demonstrate an orthogonal, counter-intuitive approach of burying the catalyst below hard-carbon framework with high pore volume to achieve superior catalytic activity (conversion ? 99%) and selectivity (? 99%) towards mono-hydrogenation of styrene to ethylbenzene, at ambient pressure and 100°C temperature. Porosity engineered nanostructured hard carbon framework (NCF) exhibits short range graphitic ordering and long-range disorder to synergistically combine accessibility in surface area (936 m2 /g, average pore diameter < 1 nm) with pore volume (0.44 cm3 /g). Nanostructured platinum (Pt) catalysts (mean diameter ?3 nm) embedded within the NCF framework (PIN) exhibits 95% higher turnover frequency as compared to the state-of-art Pt/C catalyst. This is attributed to the ability of the open-ended framework to act as a reservoir for hydrogen and thus ensure sustained pseudo-first order kinetics for hydrogenation. Such engineered heterogeneous catalysts are reusable and can be subscribed with green matrices of chemical conversions established through the near ideal values of E-factor, Process Mass Intensity (PMI) and Carbon Efficiency (CE).