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

The catalytic performance of lanthanum based catalysts: LaNiO3 and La2O3 were evaluated in the gas-phase transformation of glycerol. The reaction was investigated in the temperature range of 300-700 degrees C. At 400 and 500 degrees 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 LaNiO3 and La2O3 show no significant deactivation during 10 h at 400 degrees 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, CO2-TPD) showing that LaNiO3 was partially reduced into LaNiO2.5 during reaction at 400 degrees C. It is suggested that strong basic sites of La2O3 compared to LaNiO3 are particularly active to produce methanol through glyceraldehyde but also acetaldehyde, propionaldehyde and acetone. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.