In recent years there has been growing interest in using electrochemical methods for hydrogenation of biomass-derived molecules for the formation of biofuels. Conventional hydrogenation processes require moderate temperatures between 433 and 678 K, pressures of 14,000 kPa, and external sources of dihydrogen for the stabilization and formation of biofuels. However, the same reaction can be performed using electrochemical reactors and much lower temperatures and pressures (293 K and 101 kPa) and with no supplied dihydrogen.[1-3]<br/>In this work, we evaluate the use of heterogeneous electrocatalysts and electrocatalytic reactors for the hydrogenation of organic molecules present in biocrude. In particular, we studied the effect of electrolyte composition, concentration of substrate, metal, and cell potential on the Faradaic efficiency (FE) and catalytic activity (TOF) for the electrochemical reduction of organic molecules at normal temperature and pressure. Our results show that the reduction of biomass-derived organic molecules can be achieved electrocatalytically at normal temperature and pressure conditions. The FE of the process is affected by the metal, concentration of substrate, composition of the electrolyte, and cell potentials. Pd was found to best catalyst for the electrocatalytic reduction of organic molecules followed by Cu. We found strong correlations between reaction conditions and catalyst performance.[4] For example, the FE decreases as the cell potential increases for all the electrolytes tested regardless of the substrate and alcohol concentration in the electrolyte, suggesting that hydrogen evolution reaction (HER) is favored at high cell potentials. The FE and TOF also increase as a function of substrate concentration in the electrolyte, suggesting that the electrocatalytic hydrogenation of organics and they hydrogen evolution reactions are competitive reactions. A kinetic analysis shows that the substrate surface coverage changes as a function of cell potential and electrolyte composition.<br/><br/>

Developing electrocatalytic processes for the hydrogenation of biomass-derived molecules at normal temperature and pressure

256th National Meeting (2018)

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