Influence of Ba on Co-Al-Ba composite oxide catalysts in auto-thermal reforming of acetic acid for hydrogen production

Auto-thermal reforming (ATR) of acetic acid (HAc) is one of the potential approaches to produce hydrogen. However, the current catalysts suffered from deactivation raised from sintering and carbon deposition. In order to address these concerns, a series of Co-Al-Ba composite oxide catalysts with different Ba dopings were synthesized by Pechini method, and the activity of hydrogen production via ATR of HAc was evaluated. The CAB50 catalyst with 50 wt% of BaO presented superior activity and stability: the conversion of HAc was stable at 100%, while the hydrogen yield was maintained at 2.4 mol-H/mol HAc. This can be attributed to the replacement of Co by Ba in CoAlO spinel, hence more active species of Co were exposed over the stable BaAlO skeleton, promoting adsorption and activation of HAc with stability. Meanwhile, the TG analysis showed that suitable amount of Ba doping promoted gasification of coking precursors and relieved carbon deposition, as also proved by the SEM. [Figure not available: see fulltext.].