The design of nanoparticles with finely tuned electronic and physical properties has become a key strategy for controlling the catalytic performance in various chemical transformations. Transition metal phosphide nanoparticles have emerged as a versatile class of materials due to multi-functional active sites and phase-dependent properties for hydrotreating reactions. Modulation of the geometric and electronic structures of binary phosphides through control of morphology and crystalline structure offers the opportunity to selectively tune the catalytic performance. These properties can be further adjusted through the formation of ternary materials. Using solution-synthesis-based methods, we designed a series of ternary Ni2-xRhxP nanoparticles with fixed morphology and hexagonal crystal structure. Design of these highly controlled structures enable the deconvolution the roles of geometric and electronic properties governing activity, stability, and selectivity. In the hydrodeoxygenation of phenolic model compounds, we demonstrate that increasing Rh concentration leads to higher selectivity toward the hydrogenation pathway over the direct deoxygenation pathway. We find that the addition of Rh does not electronically modify the average Ni atom and is instead compensated by increasing P charge. Geometrically, the addition of Rh increases the metal-metal character at the surface of these nanoparticles, leading to improved interaction between the Ni2-xRhxP surface and phenyl ring, thus facilitating increased hydrogenation.

Synthetic control over ternary metal phosphides enable pathway selectivity in hydrodeoxygenation of biomass-derived model compounds

ACS Fall 2021

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