Cu-Ni bimetallic single atoms supported on TiO2@NG core-shell material for the removal of dibenzothiophene under visible light

Interactions between Cu and Ni bimetallic single atoms in catalysts prepared by precursor dilution strategy were shown to reduce the reaction energy barrier required to break the CS bond. The DBT was first catalytically oxidized to sulfone and sulfoxide, followed by in situ hydrogenation to biphenyl, and the S heteroatom was removed in the form of SO2. [Display omitted] •TiO2@Cu/Ni-NG with bimetallic Cu/Ni single-atom was prepared by a facile method.•The synergistic effect of NG, TiO2, and Cu/Ni improved the desulfurization ratios.•Catalytic oxidation coupled with in situ hydrogenation broke the C-S bond.•The interaction of Cu and Ni reduced the desulfurization reaction energy barrier.•The desulfurization ratios of 1wt% TiO2@Cu/Ni-NG achieved 100% for 120 min. Cu-Ni bimetallic single atoms supported on core–shell materials of TiO2@N-doped porous graphene were prepared using a precursor dilution strategy. HAADF-STEM and XRD results showed Cu and Ni atoms were uniformly dispersed on the surface of the N-doped porous graphene. XPS revealed the coordination environment of copper and nickel atoms, forming Cu-N4 and Ni-N4, which were conductive to the desulfurization. The photocatalytic performance of the catalysts was evaluated by the removal of dibenzothiophene from the model oil. The effect of the metal loading, temperature, reaction time, and reaction time on the desulfurization ratios was investigated. Experimental results showed the desulfurization activities of 1 wt% TiO2@Cu/Ni-NG was the best. The desulfurization ratios of DBT achieved 100% for 120 min under 30 °C, and the desulfurization ratios could still achieved 98.5% after 10 cycles. With the increase in the metal loading and reaction temperature, desulfurization ratios increased first and then decreased. The kinetics of the desulfurization reaction was established, which showed TiO2@Cu/Ni-NG could reduce the activation energy and accelerate the reaction rate because of the synergistic effect between the Cu and Ni single-atom loaded on the surface of nitrogen-doped graphene. The simple and universal preparation process of TiO2@Cu/Ni-NG makes it have a good application prospect.