Insights into the coupling of H2S adsorption and subsequent C4H4S hydrogenation over Ni–Mo composite adsorbents

Metal oxides-based adsorbents used for desulfurization encounter significant challenges during practical application owing to their inferior reusability and the nature of solid waste of their desulfurization products. This situation might be alleviated to some extent through a rational design of Ni–Mo composite, enabling them firstly to be used as adsorbents for H 2 S removal, and then being utilized as catalysts after desulfurization for C 4 H 4 S hydrogenation. The Ni–Mo composites before and after desulfurization were characterized using XRD, FT-IR, SEM, N 2 adsorption–desorption, XPS, CO 2 -TPD and H 2 -TPR techniques. The experimental findings suggested that Ni and Mo species function as primary active sites for H 2 S adsorption and C 4 H 4 S hydrogenation reactions, respectively. The Ni and Mo composite greatly facilitated the coupling of these two reactions due to the formation of NiMoO 4 phase. This novel active phase not only boosted the interaction between metal and H 2 S but also promoted the formation of weak and moderate alkaline sites, thereby significantly enhancing desulfurization performance. Importantly, this active phase fostered the sulfurization of Mo species and transforming into a Ni–Mo–S component, further favoring the subsequent catalytic reaction in C 4 H 4 S hydrogenation. Consequently, the prepared Ni–Mo composite oxides exhibited excellent properties in H 2 S adsorption and C 4 H 4 S hydrogenation activity, surpassing the capabilities of single metal adsorbents and commercial hydrogenation catalysts.