Synthesis and characterization of Ni-Co on different composition support towards hydrogen production from acetic acid steam reforming

Abstract

Hydrogen is being considered as an alternative source for power generation in the future. The development of environmental friendly and cost effective hydrogen production become the main challenge in this area. In this work, the production of hydrogen by steam reforming of acetic acid over nickel-cobalt (Ni-Co) supported on lanthanum oxide (La2O3), cerium oxide (CeO2) and aluminum oxide (Al2O3) was studied. The objectives of this study are to prepare the catalyst using an impregnation method, to characterize the catalyst using Temperature Programmed Desorption (TPD-NH3), Brunauer-Emmett-Teller with N2 (BET-N2) and Temperature Programmed Reduction with H2 (TPR-H2) analysis and also to study the effect of reaction temperature on acetic acid conversion. TPR- analysis of the samples indicated that the amount of hydrogen consumed by the catalyst supported with same oxides decreases with increasing amount of La2O3. Furthermore, Ni- Co/70%La2O3-20%CeO2 catalyst was reduced at lower temperature compared to other three catalysts. The result of TPD-NH3 also showed that the acidity of the catalysts reduced by reducing the amount of ceria. Meanwhile, steam reforming of acetic acid was conducted in a fixed bed reactor with metal catalysts on different supports metal at temperature of 600 oC, atmospheric pressure, 0.36 ml/min flow rate, acetic acid concentration 10 wt% and the weight of catalyst was 0.2 g. It was found that the mole fraction of hydrogen over Ni-Co/70%La2O3-20%Al2O3 catalyst was the highest which is 0.59, while acetic acid conversion over Ni-Co/70%La2O3- 20%CeO2 catalyst was the highest 93%. In addition, the catalyst (Ni-Co/70%La2O3- 20%CeO2 and Ni-Co/80%La2O3-10%CeO2) performance tests are carried out in a fixed bed reactor at atmospheric pressure and temperature from 500°C to 700°C at increment of 50°C/min, 0.36ml/min flow rate and 10 wt% acetic acid concentration. It was found that the hydrogen production dropped by increasing of temperature and the temperature of 500 to 550oC produce the high amount of hydrogen.