The SiO2 supported bimetallic Ni–Ru particles: A good sulfur-tolerant catalyst for methanation reaction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2015-01, Vol.260, p.1-10
• Main Authors: Yuan, Changkun, Yao, Nan, Wang, Xinde, Wang, Jianguo, Lv, Deyi, Li, Xiaonian
• Format: Article
• Language: English
• Subjects: Bimetallic Ni–Ru particle; Catalyst; Long-term stability; Methanation; Sulfur tolerance
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2014.08.079

•Addition of H2S enhances the sintering and oxidation of Ni0 particle in the methanation reaction.•Effect of Ru on the sulfur tolerance of the supported Ni catalyst depends on its geometric factor.•Adsorption of S can only be reduced when S binds with Ni and Ru atoms simultaneously.•S can bind with Ni and Ru atoms simultaneously on the small bimetallic Ni–Ru particles.•NiRu/SiO2 catalyst with small bimetallic Ni–Ru particles has enhanced sulfur tolerance. The long-term stabilities and the sulfur tolerances of SiO2 supported Ni and NiRu catalysts in the methanation reaction were examined. The presence of H2S molecules (10ppm (v/v)) in the syngas led to fast deactivation of Ni/SiO2 catalyst, because the adsorption of S blocked the active sites as well as accelerated the sintering and the oxidation of Ni0 particles. The effect of Ru on the reduction of S adsorption over the supported Ni-based catalyst depended on its geometric instead of electronic factor. The S adsorption could only be weakened when S bound with both Ni and Ru atoms simultaneously. The formation of such state was more favorable on the polyethylene glycol (PEG)-additive method derived NiRu/SiO2 catalyst with small bimetallic Ni–Ru particles. As a result, this catalyst could stabilize for ∼127h in H2S-containing methanation reaction, which was ∼1.6–5.8-fold longer than those of PEG-free method derived NiRu/SiO2 catalyst (∼79h) with separated Ru and Ni/SiO2 catalyst (∼22h).