Oxidative Dehydrogenation of Ethane with CO2 over Flame-Made Ga-Loaded TiO2

Abstract

The influence of the Ga content (0–17 wt %) on the structural properties and the catalytic behavior of flame-synthesized TiO2-supported gallium oxide in the oxidative dehydrogenation of ethane (ODHE) has been investigated in a continuous tubular microreactor using CO2 as a mild oxidant. The gallium oxide–titania powders consisted of nonporous spherical particles of about 10 nm average diameter, as indicated by HRTEM and X-ray line broadening, and had a specific surface area of about 120 m2/g. XRD showed no reflections corresponding to Ga2O3 in the as-prepared samples, indicating high dispersion of the Ga constituent. At higher Ga loading (>14 wt %) stronger acidic sites became prominent, as indicated by NH3-TPD and DRIFTS. The ethene yield increased with Ga loading up to about 10 wt %. The molar CO2/C2H6 ratio in the feed, reaction temperature, and space velocity were decisive parameters for achieving maximum ethene yield. The ethene yield achieved was 22% using a CO2/C2H6 ratio of 2.5, 700 °C, and a spac...