Sulfated zirconia was synthesized by a one step solvent-free method, directly mixing Zr­(OH)4 and (NH4)2SO4. The entire synthesis process produces no wastewater, which is environmentally friendly. The synthesis factor (mole ratio of (NH4)2SO4:Zr­(OH)4) is the main point to test catalytic activity. Structural properties are characterized by X-ray diffraction (XRD), N2 adsorption–desorption isotherms, and inductively coupled plasma (ICP). The acid property is characterized by pyridine-FTIR. The S coverage (×10–6 mol S·m–2)–Lewis acidic sites density (mmol·m–2) relationship in sulfated zirconia reveals that the generation order of Lewis acidic sites is from weak ones to strong ones. Calculation of acid property reveals the positive structural–functional relationship (WL/SL–catalytic activity). Weak Lewis acidic sites (WL) promote the activity toward removal olefins, while strong Lewis acidic sites (SL) speed up the deactivation of catalysts. The superior catalytic performance as well as environmentally friendly synthesis method demonstrates that solvent-free sulfated zirconia has bright application prospects in industry.

A series of sulfated zirconia (SZ) catalysts was synthesized by immersion of amorphous zirconium hydroxide in sulfuric acid of various concentrations (1 to 5 N). These samples were fully characterized by X-ray diffraction (XRD), thermogravimetric analysis and mass spectrometry (TGA-MS), and aqueous sulfuric acid immersion and high temperature oxide melt solution calorimetry. We investigated the enthalpies of the complex interactions between sulfur species and the zirconia surface (∆H sz) for the sulfated zirconia precursor (SZP), ranging from-109.46 ± 7.33 (1 N) to-42.50 ± 0.89 (4 N) kJ/mol S. ∆H sz appears to be a roughly exponential function of sulfuric acid concentration. On the other hand, the enthalpy of SZ formation (∆H f), becomes more exothermic linearly as sulfur surface coverage increases, from-147.90 ± 4.16 (2.29 nm-2) to-317.03 ± 4.20 (2.14 nm-2) kJ/mol S, indicating stronger sulfur specieszirconia bonding.

Incorporating Al into zirconia significantly improves and stabilizes the surface sulfur species. The outstanding catalytic performance of Al-incorporated sulfated zirconia was obtained when it was applied in removing trace olefins from aromatics.

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Selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE) has been studied on the silicalite-1/CuY core–shell composites. Different copper ion sources (CuCl2, Cu­(NO3)2, and CuSO4) were investigated to form CuY as the core by Cu2+ ion-exchange on NaY zeolite. These silicalite-1/CuY core–shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/tetrapropylammonium hydroxide (TPAOH)/ethanol/H2O/CuY = 20 g:19 g:17 g:87 g:5 g. Results showed that the core–shell Y-CuCl2 displayed the best performance in desulfurization of DMDS with a sulfur adsorption capacity of 32.882 mgs/gadsorbent, owing to its significant mass gain and compact coatings after being coated by silicalite-1 on Y-CuCl2. Also, the preparation process of CuY and the shape selective adsorption mechanism of desulfurizing DMDS from MTBE on the silicalite-1/CuY core–shell composites were expounded.

A high-aluminum-content sulfated zirconia was prepared by the kneading method, and the washing process was considered as a key factor. Catalysts were characterized by XRD, BET analysis, SEM, TG, FT-IR spectroscopy, pyridine IR spectroscopy, NH 3 TPD, H 2 TPR, and 27 Al NMR spectroscopy, and the reactivity was evaluated by n-hexane isomerization. The results showed that the high-aluminum-content sulfated zirconia has a high activity after being washed with water. Moreover, the aluminum content was found to strongly influence the crystal form, catalyst structure, and acidity, as well as the anchoring effect on the labile sulfates. Actually, the higher the aluminum content was, the more sulfates were left in the catalyst samples after washing. The OH and SO stretching vibrations were shifted in the presence of aluminum or water. With the support of the aluminum coordination state, a hydrolysis model was deduced for different aluminum contents in the catalysts, and it can explain the formation of more Brønsted acid sites and AlOS bonds.