(675b) Oxidative Dehydrogenation of Ethane over Boron Containing Chabazite

Boron-containing heterogeneous catalysts, such as hexagonal boron nitride (h-BN), metal borides, and boron oxides, have high catalytic activity in the oxidative dehydrogenation (ODH) of propane to propylene, with excellent selectivity towards olefin compounds. Few catalysts, however, are utilized in the ODH of ethane (ODHE) to ethylene. Steam cracking, the main industrial ethylene production method, requires a high operating temperature and produces vast amounts of GHG emissions. It is very desirable to develop other ethylene production methods.

We will describe the catalytic properties of a boron-containing zeolite with chabazite framework (B-CHA), which shows excellent conversion of over 22% at 580 ^oC in the ODHE, with selectivity of more than 87% towards ethylene. The stability of the B-CHA catalyst was tested and we found that B-CHA achieves even higher conversion (27%) than at the beginning and maintains high ethylene selectivity (86%) after 60 h of reaction. A kinetics study regarding the activation energy, oxygen and ethane partial pressure dependences on the ethane consumption rate is also investigated. Several characterization methods including 1D and 2D boron NMR, FTIR, UV-Vis and XPS are used in the identification of active sites. A combination of the kinetic study and the identification of boron species, we propose the ODHE reaction network over the B-CHA catalyst.