Influence of precursors used in preparation of MgO on its surface properties and catalytic activity in oxidative coupling of methane

Abstract

Surface properties (viz., acidity/acid strength distribution, basicity/base strength distribution, surface area, morphology, and surface composition) and catalytic activity/selectivity in the oxidative coupling of methane at different process conditions [reaction temperature, 700-800°C; CH₄/O₂ ratio, 3.0-8.0; and gas hourly space velocity (GHSV), 25,500-102,000 cm³ . g^-1 . h^-1)] of MgO obtained by thermal decomposition of hydrated MgO, magnesium hydroxide, magnesium nitrate, magnesium acetate, and magnesium carbonate have been investigated. The surface and catalytic properties are found to be strongly affected by the precursors used in the preparation of MgO. The catalytic activity and selectivity (for ethane and ethylene) of MgO obtained from magnesium carbonate and magnesium acetate are comparable and are much higher than that observed for MgO obtained from the other precursors.