Owing to their use in many industrial reactions, nanoparticle metal catalysts deposited on high surface area metal oxide supports are an intensely studied class of materials. Studies that focus on model catalyst systems can allow the experimenter to simultaneously probe important fundamental phenomena, such as catalyst-support interactions, while obtaining state-of-the-art catalytic performance. Platinum (Pt) nanoparticles deposited onto SrTiO3 (STO) nanocuboids (Pt/STO), a catalyst-support combination that exhibits cube-on-cube epitaxy, has previously been reported as such a model system. There is considerable incentive for further study of the Pt/STO system for waste plastic upcycling of polyolefins, which is a largely unexplored field with potentially wide-ranging economic and ecological impacts. Towards that goal, we report a scalable hydrothermal synthesis for STO NCs that produces nanoparticles ranging from 25 to 80 nm with narrow size distributions and more reliably controls for nanoparticles with a cuboid morphology. These nanocuboids were used to support Pt deposited through strong electrostatic adsorption (SEA), a precise yet straightforward method for solution-phase catalyst deposition. Using SEA techniques and a STO support with an average size of 39.3 ± 6.3 nm, a Pt/STO catalyst with 3.6 wt% Pt was produced and used to upcycle high-density polyethylene by hydrogenolysis to a highly-uniform waxlike product (170 psi H2, 300°C, 96h; final product: Mw = 2400, D = 1.03). We will continue to explore how changes to global conditions during Pt/STO synthesis impact pertinent catalyst physical properties, such as particle size and dispersion, and how these in turn influence product distributions obtained during waste plastic upcycling.

Synthesis of Pt/SrTiO3 upcycling catalysts with controlled support shape, particle size, and catalyst dispersion

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.