An Atomistic Picture of Boron Oxide Catalysts for Oxidative Dehydrogenation Revealed by Ultrahigh Field <sup>11</sup>B–<sup>17</sup>O Solid-State NMR Spectroscopy
Rick W. Dorn, Lesli O. Mark, Ivan Hung, Melissa C. Cendejas, Yijue Xu, Peter L. Gor’kov, Wenping Mao, Faysal Ibrahim, Zhehong Gan, Ive Hermans, Aaron J. Rossini
Abstract
Boron oxide/hydroxide supported on oxidized activated carbon (B/OAC) was shown to be an inexpensive catalyst for the oxidative dehydrogenation (ODH) of propane that offers activity and selectivity comparable to boron nitride. Here, we obtain an atomistic picture of the boron oxide/hydroxide layer in B/OAC by using 35.2 T 11B and 17O solid-state NMR experiments. NMR spectra measured at 35.2 T resolve the boron and oxygen sites due to narrowing of the central-transition powder patterns. A 35.2 T 2D 11B{17O} dipolar heteronuclear correlation NMR spectrum revealed the structural connectivity between boron and oxygen atoms. The approach outlined here should be generally applicable to determine atomistic structures of heterogeneous catalysts containing quadrupolar nuclei.