(669f) Atomically Dispersed Pt Catalysts on Polyphosphomolybdic Acid: Structural Features and Catalytic Properties

Yan, N., National University of Singapore
Single-atom catalyst (SAC), referring to a class of catalysts where bare metal atoms are atomically dispersed or anchored on the support, has recently emerged as a new frontier in heterogeneous catalysis.[1] A key challenge encountered, however, is to stabilize isolated metals on a support without compromising catalytic activity.

In coordination chemistry, catalytically active metal complexes in zero or low valent state often adopt four-coordinate square-planar or tetrahedron geometry. By applying this principle, we have developed stable, high loading (close to 1 wt%), Pt1single-atom catalyst on phosphomolybdic acid modified active carbon, by anchoring Pt on the four-fold hollow sites on PMA. Each Pt atom is stabilized by four oxygen atoms in a distorted square-planar geometry, with Pt slightly protruding from the oxygen planar surface. Pt is positively charged, easily absorbs hydrogen, and exhibits excellent performance in the hydrogenation of nitrobenzene and cyclohexanone. The system described here is likely to be extended to a number of stable SACs with superior catalytic activities.[2]

1. a) Flytzani-Stephanopoulos, M.; Gates, B.C. Annu. Rev. Chem. Biomol. Eng. 2012, 3, 545-574; b) Thomas, J.M. Nature 2015, 525, 325-326.

2. Zhang, B.; Asakura, H.; Zhang, J.; Zhang, J.; De, S.; Yan, N. Angew. Chem. Int. Ed., 2016, DOI: 10.1002/anie.201602801R1.