Study on the preparation of Ni–La–Ce oxide catalyst for steam reforming of ethanol

• NiO supported on solid solution was made according to citrate complexing method.
• LaNiO3 supported on ceria was prepared by using impregnation method.
• Both of the catalysts showed excellent performance for ethanol steam reforming.
• The investigated catalysts showed very good anti-sintering ability.
• Oxygen vacancies presented better ability to remove carbon than La2O2CO3.

Two schemes for design and preparation of Ni–La–Ce oxide catalysts for steam reforming of ethanol were proposed in this work. The one via citrate complexing method was designed as NiO supported on ceria-lanthanum oxide (CL) solid solution, in which the strong interaction between NiO and CL solid solution was beneficial to inhibit the aggregation of NiO particles, and the abundant of oxygen vacancies existed in CL solid solution was in favor of carbon elimination from catalyst surface. The other was schemed as LaNiO3 with perovskite structure loaded on CeO2 support by using impregnation method, in which the particles of metal Ni derived from reduction of LaNiO3 were highly dispersed, and the formation of La2O2CO3 in the reaction process could act as the carbon scavenger. Both of the catalysts exhibited very good performance for steam reforming of ethanol (SRE), complete C2H5OH conversion was obtained with 70.3% of H2 selectivity at 400 °C over the catalyst obtained from former method and complete C2H5OH conversion was achieved at 450 °C with 67% of H2 selectivity over the catalyst from latter method. The catalyst made according to the citrate complexing method was more active for SRE and more selective for H2 production. Both of the catalysts displayed very good anti-sintering ability which was tested at 650 °C and at a high space velocity of 180,000 ml gcat−1 h−1 with reaction mixture of H2O/C2H5OH = 3 in mole ratio. The results indicated that both of oxygen vacancy and La2O2CO3 possessed the ability to remove the deposited carbon, and compared with La2O2CO3 the oxygen vacancy could reduce one third more of the carbon deposited according to TG tests.