A new class of TiO₂-doped CeO₂ nanorods was synthesized via a modified hydrothermal method, and these nanorods were first used as catalysts for the direct synthesis of dimethyl carbonate (DMC) from CO₂ and CH₃OH in a fixed-bed reactor. The micromorphologies and physical–chemical properties of nanorods were characterized by transmission electron microscopy, X-ray diffraction, N₂ adsorption, inductively coupled plasma atomic emission spectrometry, X-ray photoelectron spectroscopy, and temperature-programmed desorption of ammonia and carbon dioxide (NH₃-TPD and CO₂-TPD). The effects of the TiO₂ doping ratio on the catalytic performances were fully investigated. By doping TiO₂, the surface acid–base sites of CeO₂ nanorods can be obviously promoted and the catalytic activity can be raised evidently. Ti_0.04Ce_0.96O₂ nanorod catalysts exhibited remarkably high activity with a methanol conversion of 5.38% with DMC selectivity of 83.1%. Furthermore, kinetic and mechanistic investigations based on the initial rate method were conducted. Over the Ti_0.04Ce_0.96O₂ nanorod catalyst, the apparent activation energy of the reaction was 46.3 kJ/mol. The reaction rate law was determined to be of positive first-order to the CO₂ concentration and the catalyst loading amount. These results were practically identical with the prediction of the Langmuir–Hinshelwood mechanism in which the steps of CO₂ adsorption and activation are considered as rate-determining steps.

High-molecular-weight poly(arylene thioether ketone) (PTK) and poly(arylene thioether ketone ketone) (PTKK) polymers were successfully synthesized by one-pot polymerization of N,N′-dimethy-S-carbamate masked dithiols with activated dihalo compounds, followed by post-sulfonation using chlorosulfonic acid as the sulfonation agent in dichloromethane solution to give the production of sulfonated poly(arylene thioether ketone) (SPTK) and sulfonated poly(arylene thioether ketone ketone) (SPTKK) with appropriate ion-exchange capacities. The chemical structures were confirmed by ¹H NMR, FT-IR and elemental analysis (EA). The thermal properties were fully investigated by TGA-IR. The synthesized SPTK and SPTKK polymers are soluble in aprotic solvents such as N,N′-dimethylacetamide (DMAc), N,N′-dimethylformamide and dimethyl sulfoxide, and can be cast into membranes on a glass plate from their DMAc solution. The proton conductivities of these membranes are comparable to Nafion117 membranes under the same conditions. Cell performance tests showed that the vanadium redox flow batteries (VRBs) assembled with SPTK and SPTKK membranes possessed higher Coulombic efficiencies than VRBs assembled with Nafion117 membranes at the current density of 50 mA cm⁻², because of their one-order-of magnitude lower VO²⁺ permeabilities. In conclusion, these ionomers could be promising candidates as proton-exchange membranes for vanadium redox flow battery (VRB) applications.