Effect of NiO Loading and Thermal Treatment Duration on Performance of Ni/SBA-15 Catalyst in Combined Steam and CO₂ Reforming of CH₄

Abstract

A series of Ni/SBA-15 catalysts was prepared by impregnation method. Effect of NiO content (3060 mass%), calcination time (0.52 h at 800°C), and reduction time (12 h at 800°C) on catalytic performance in combined steam and CO 2 reforming of CH 4 (CSCRM) was studied. N 2 physisorption measurements, powder X-ray diffraction, Hydrogen temperature-programmed reduction, CO 2-temperature-programmed desorption, and transmission electron microscopy were used to investigate physico-chemical properties of the catalysts. The catalytic performance of Ni/SBA-15 in CSCRM was assessed in the temperature range of 550800°C. The results revealed suitable time for calcination and reduction being 0.5 h and 1.5 h, respectively. After these treatments, 40 mass% NiO/SBA-15 catalyst was more active and exhibited higher activity than others. At 750°C, conversion of CH 4 and CO 2 on this catalyst in CSCRM was 91.05% and 78.11%, respectively. High surface area, better reducibility, and good affinity with CO 2 contribute to the high performance of this catalyst.

Effect of NH3 Alkalization and MgO Promotion on the Performance of Ni/SBA-15 Catalyst in Combined Steam and Carbon Dioxide Reforming of Methane

“…SBA-15 was prepared by the method described in the work [9]. To prepare SBA-15 alkalized with ammonia solution (SBA-15-NH 3 ), 2 grams of SBA-15 was put into beakers containing 50 ml NH 3(aq) solution with various concentrations, 10%, 15%, 20%, and 25% in volume, respectively.…”

“…To prepare SBA-15 alkalized with ammonia solution (SBA-15-NH 3 ), 2 grams of SBA-15 was put into beakers containing 50 ml NH 3(aq) solution with various concentrations, 10%, 15%, 20%, and 25% in volume, respectively. These mixtures were then placed in an autoclave at 160°C for 10 h. After that, they were washed with distilled water and dried at 120°C for 2 h. Then, NiO supported on SBA-15-NH 3 catalysts were prepared by impregnating Ni(NO 3 ) 2 solution on SBA-15-NH 3 according to the procedure described in reported work [9]. The Ni content in the catalysts was fixed at 31.4 wt.% (or 40 wt.%NiO).…”

“…-TPD were carried out on a microreactor with a sample of 50 mg using a Gas Chromatograph GOW-MAC 69-350 with a thermal conductivity detector (TCD). The activity of catalysts for bireforming was tested in a microflow reactor under atmospheric pressure at a temperature of 550-800°C as described in detail in our previous paper [9]. Briefly, a catalyst sample of 0.2 grams, the feed flow rate of 6 L/h, CH 4 concentration in feed of 3 mol.%, and the molar ratio of CH 4 : CO 2 : H 2 O in feed of 3 : 1.2 : 2.4 was used in the investigation.…”

“…However, to the best of our knowledge, the impact of treatment with aqueous NH 3 step in catalyst preparation or promoting catalysts by MgO on the activity of Ni/SBA-15 catalyst in bireforming has not been carried out so far. In our previous investigation [9], it was reported that NiO/SBA-15 catalyst contained 31. 4…”

“…In our previous study [9], nanosized NiO/SBA-15 catalysts with NiO crystallite size in the range of 12.9 to 18.3 nm were successfully prepared. In this catalytic system, there are 5-6 nm NiO particles dispersed inside the pores and the NiO particles of 20-50 nm distributed on the surface of SBA-15 when Ni content was 23.5-39.2 wt.%.…”