Catalysis Today, Vol.355, 415-421, 2020
The regulatory effect of Al atomic-scale doping in NiAlO for COS removal
In this paper, Al atomic-scale doping has been achieved by using NiAl hydrotalcite-like compounds (HTLCs) as precursors method. Regulatory effect of Al doping in NiO for carbonyl sulfide (COS) removal was studied. The samples were systematically characterized by XRD, SEM, N-2 adsorption/desorption, FTIR, CO2-TPD, XPS, XAFS and In-situ DRIFTS. The results showed that the activity series for removal of COS decrease in the following sequence: Ni3Al-HTO > Ni5Al-HTO > NilAl-HTO. The enhanced activity after Al atomic-scale doping is attributed to the abundant surface basic sites as evidenced by results of CO2-TPD. XPS and XAFS provide evidence for the reduction of Ni2+ by Al doping in NiO, which suggest large amounts of O-vacancies present on Ni3Al-HTO. This work is useful to explore feasible routes to improve the performance of desulfurization material for the feed gas purification.