Remarkably high performance of clew-like ZnO superstructure in reactive adsorption desulfurization

Abstract

In this study, a clew-like ZnO superstructure was synthesized by a copolymer-controlled self-assembly homogeneous precipitation method. Ni was impregnated to the clew-like ZnO superstructure to obtain Ni/ZnO adsorbents. The synthesized materials were characterized by scanning electron microscopy, transmission electron microscopy, N2 sorption, X-ray diffraction, Fourier transform infrared spectrometry, and H2-temperature programmed reduction techniques. The reactive adsorption desulfurization (RADS) performance of the adsorbents was evaluated in a fixed bed reactor using thiophene in n-octane as a model fuel. Sample Ni/ZnO-4h exhibits a remarkably high performance with a sulfur capacity of 189.1 mg S g–1, which is above 6 times that of the one prepared with commercial ZnO. Characterization results show that the morphology changes from micro-clews to large solid sticks with the increase of the crystallization time. The loose and open architecture of the clew-like ZnO superstructure facilitates the diffusion of reactants/products, and prevents the adsorbent particles from breakage by supplying space for the volume expansion during the RADS process. The small nanoparticles in ZnO nanostrips result in a high sulfur adsorption capacity and also favor the dispersion of Ni, leading to an excellent RADS performance.