Gas phase glycerol conversion over lanthanum based catalysts: LaNiO3 and La2O3

Abstract The catalytic performance of lanthanum based catalysts: LaNiO 3 and La 2 O 3 were evaluated in the gas-phase transformation of glycerol. The reaction was investigated in the temperature range of 300–700 °C. At 400 and 500 °C, the production of compounds in liquid phase is favored while at high temperature gases such as carbon monoxide, carbon dioxide and hydrogen are mainly formed. The basic catalysts used in this study favor the production of hydroxyacetone. Additionally 1,2 propanediol, methanol and ethylene glycol were formed in significant amount. The perovskite LaNiO 3 and La 2 O 3 show no significant deactivation during 10 h at 400 °C, the selectivity to hydroxyacetone only slightly decreased with time on stream most probably due to the formation of heavy products. The catalysts were characterized before and after reaction (XRD, TGA, CO 2 -TPD) showing that LaNiO 3 was partially reduced into LaNiO 2.5 during reaction at 400 °C. It is suggested that strong basic sites of La 2 O 3 compared to LaNiO 3 are particularly active to produce methanol through glyceraldehyde but also acetaldehyde, propionaldehyde and acetone.