Oxygen‐Functionalized Boron Nitride for the Oxidative Dehydrogenation of Propane – The Case for Supported Liquid Phase Catalysis

Boron and boron containing materials have created a new class of catalysts for the highly selective conversion of light alkanes to building block olefins. Boron oxide species seem to play an essential role for the oxidative dehydrogenation of propane. For boron nitride they are created through an induction process under reaction conditions. It is still not obvious how different kinds of oxidative pre-activation influences the observed activity and selectivity. Here we compare two different oxygen activation strategies of boron nitride, a classical activation by calcination at different temperatures and ball-milling with varying rotation velocity. These treatments allow to control the amount of introduced boron oxide species from 0.2 to 17.5 wt.-%, as quantified by alkalimetric titration. The catalytic experimental data together with the pre, post as well as in situ characterization, give insights how the catalyst's surface changes under reaction conditions. On this backdrop it can be deduced that molten boron oxide predominantly acts as catalyst under reaction conditions, and boron nitride as catalyst support.