Directed aqueous-phase reforming of glycerol through tailored platinum nanoparticles

Suggested sites for differing reaction pathways in the APR of glycerol. [Display omitted] •Demonstration of how Pt NP size can be tuned by changing the temperature of colloidal reduction.•The influence of Pt NP size on the selectivity profile of the APR of glycerol.•Mechanistic insight into reaction pathways and the influence of Pt NP size. Sustainable technologies require both renewable feedstocks and catalysts that are able to direct their conversion to specific products. We establish a structure-activity relationship for the aqueous phase reforming of glycerol over 2% Pt/Al2O3 catalysts, whereby the reaction pathway can be controlled to produce either hydrogen or 1,2-propanediol as the main product. Using the colloidal synthesis method, the reduction temperature was altered to produce Pt nanoparticle catalysts supported on Al2O3 with varying Pt particle size. The catalytic activity of the samples for the APR of glycerol resulted in a higher conversion of glycerol (34%) for the larger Pt particle size of ∼3.5 nm, producing the liquid 1,2-propanediol as the major product with a yield of 12.5%, whereas smaller particles of ∼2.2 nm gave hydrogen as the main product (5.5% yield). This work demonstrates how the APR of glycerol can be tuned to yield both valuable liquid and gas products using tailored Pt nanoparticles.