| As a result of the expansion of biodiesel utilization, the production of glycerol, the principal by-product of biodiesel production, has increased significantly. To make the biodiesel supply chain more viable, there is significant interest in converting glycerol into valuable chemicals and gases.;The use of a proton-exchange-membrane (PEM) reactor to produce value-added chemicals from glycerol was investigated. Based on a catalyst screening using a solid-state cell, Pt was selected as a primary metal to study activity and selectivity of glycerol oxidation by supporting on carbon and alloying with other metals.;The rate and selectivity of glycerol oxidation was evaluated for Pt/C and Pt-Ru/C in a PEM reactor. Both catalysts showed similar rate constants while exhibiting substantial differences in selectivity towards glyceraldehyde. Further investigation suggested that this selectivity change was due to the nature of the glycerol adsorption mechanisms on these catalysts' surfaces, which significantly affected the subsequent reaction pathways. On the Pt-Ru surface, glycerol adsorption and desorption seemed more facile than on the Pt surface, possibly due to the modification of the electronic structures.;Key details regarding the catalyst deactivation mechanisms are also discussed. A series of experimental and theoretical studies suggest the existence of combined deactivation mechanisms occurring during glycerol oxidation in a PEM reactor. The main contribution could be carbon deposition, CO poisoning, and carbon support corrosion. Most of these deactivations can be minimized by lowering the operating potential, which may be a trade-off between activity and durability.;With this understanding of the glycerol oxidation mechanism, a Pt-alloy could be developed as a selective catalyst for glycerol oxidation in a PEM reactor to produce commodity chemicals. However, simultaneous management of catalyst deactivation is required to ensure the long-term and stable operation of the reactor. |
