Abstract
Palladium is one of the few metals capable of forming hydrides, with the catalytic properties being dependent on the elemental composition and spatial distribution of H atoms in the lattice. Herein, we report a facile method for the complete transformation of Pd nanocubes into a stable phase made of PdH0.706 by treating them with aqueous hydrazine at a concentration as low as 9.2 mM. Using formic acid oxidation (FAO) as a model reaction, we systematically investigated the structure-catalytic property relationship of the resultant nanocubes with different degrees of hydride formation. The current density at 0.4 V was enhanced by four times when the nanocubes were completely converted from Pd to PdH0.706. On the basis of a set of slab models with PdH(100) overlayers on Pd(100), we conducted density functional theory calculations to demonstrate that the degree of hybrid formation could influence both the activity and selectivity toward FAO by modulating the relative stability of formate (HCOO) and carboxyl (COOH) intermediates. This work provides a viable strategy for augmenting the performance of Pd-based catalysts toward various reactions without altering the loading of this scarce metal.
| Original language | English |
|---|---|
| Pages (from-to) | 2556-2568 |
| Number of pages | 13 |
| Journal | Journal of the American Chemical Society |
| Volume | 144 |
| Issue number | 6 |
| DOIs | |
| State | Published - Feb 16 2022 |
Funding
This work was supported in part by the Department of Energy, Office of Basic Energy Sciences, Catalysis Science Program (Grant DE-FG02-05ER15731) and start-up funds from the Georgia Institute of Technology. The electron microscopy, XPS, and XRD analyses were conducted at the Institute of Electronics and Nanotechnology (IEN, Georgia Institute of Technology), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (ECCS-2025462). Part of the computational work was carried out using supercomputing resources at the National Energy Research Scientific Computing Center (NERSC). NERSC is supported by the U.S. Department of Energy, Office of Science, under Contract DE-AC02-05CH11231. The monochromated EELS analysis was supported by an Early Career project supported by DOE Office of Science FWP #ERKCZ55-KC040304 and was performed at Oak Ridge National Laboratory’s (ORNL) Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility.