Yiqun Fan

With significant advances in alkane dehydrogenation in recent years, the direct CO2 hydrogenation to light alkanes (ethane, propane, and butanes) over an oxide/zeolite (OXZEO) composite catalyst offers a pathway for light olefin production. Nevertheless, the existing CO2-to-alkanes conversion often relies on the strong acid sites in zeolite micropores for olefin hydrogenation, which tends to cause side reactions and coking. Herein, we discovered the Ni-doping on a CdZrOx catalyst not only enhanced the density of oxygen vacancy for efficient CO2 activation but also promoted the H2 dissociation and spillover capacity. When combined with SAPO-34 aluminophosphate with medium acidity, the NiCdZrOx(0.05)/SAPO-34(0.075) bifunctional system converted CO2 and H2 directly into light alkanes (C20–C40) with an alkane-in-hydrocarbons selectivity of 81% and CO2 conversion of 40% at 350 °C and 4 MPa, maintaining its stability for 100 h. In situ X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis and density functional theory (DFT) calculations attributed the robust catalytic performance to a tailored reaction pathway: CO2 and H2 were efficiently activated on NiCdZrOx(0.05) to form a methanol intermediate, which then migrated to the moderately acidic SAPO-34 aluminophosphate and underwent a controlled methanol-to-olefins (MTO) reaction. The generation of active hydrogen species due to the strong hydrogen spillover effect of NiCdZrOx(0.05) drove the secondary hydrogenation of light olefins into corresponding alkanes. Moreover, the hydrogen spillover also effectively minimized the coke deposition in SAPO-34 micropores, thereby significantly promoting the catalytic activity and stability of CO2 hydrogenation to light alkanes.

Ultrathin yttria-stabilized zirconia (YSZ) electrolyte membranes are critical for reducing ohmic resistance and enabling intermediate-temperature operation of solid oxide fuel cells (SOFCs). However, the fabrication of gas-tight electrolytes with micrometer-scale thickness on porous anode supports remains challenging due to capillary infiltration and structural instability during liquid-membrane formation. Herein, a UV-curing-assisted dip-coating strategy is proposed to fundamentally regulate the formation and stabilization of ultrathin YSZ electrolyte membranes. By employing a resin-based ceramic slurry with tailored rheological properties and low surface tension, capillary penetration into porous anode substrates is effectively suppressed, enabling the formation of uniform and continuous liquid membranes. Subsequent ultraviolet curing induces rapid cross-linking of the resin matrix, generating a transient supporting skeleton that stabilizes the green membrane and prevents particle migration and collapse. Through optimization of slurry solid content and sintering protocols guided by thermal decomposition behavior, dense and defect-free YSZ electrolyte membranes with a minimum thickness of approximately 2 μm are successfully fabricated. Single cells assembled with the ultrathin electrolytes deliver peak power densities of 750 mW cm−2 at 800 °C and 150 mW cm−2 at 650 °C, demonstrating excellent gas tightness and stable electrochemical performance. This scalable and low-cost UV-curing-assisted dip-coating approach provides a versatile pathway for the controlled fabrication of ultrathin oxide electrolyte membranes on porous supports, with broad applicability to intermediate-temperature SOFCs and related electrochemical devices.

Ceramic tight ultrafiltration (UF) membranes exhibit excellent chemical and thermal stability. However, increased pore size and limited separation accuracy caused by high temperature sintering remain challenges in their preparation and application. In this study, a facile lattice-doping strategy using Fe-doped sol-gel precursors was developed to fabricate α-Al₂O₃ tight UF membranes. Fe incorporation effectively promoted the γ → α phase transformation at a reduced temperature (950 °C), suppressed grain growth, and produced smaller and more uniformly distributed pores with an average size of 5.5 nm. Increasing Fe content further enhanced surface hydrophilicity, corrosion resistance in biotic systems, and pure-water permeability (130 L·m^-2·h^-1·bar^-1). Nevertheless, excessive Fe loading (>10%) resulted in phase separation and pore size heterogeneity. The optimized 10% Fe-doped α-Al₂O₃ membrane exhibited outstanding separation performance, achieving a BSA rejection of 99.9% and a permeance of 80 L·m^-2·h^-1·bar^-1, nearly double the value of the undoped membrane. It also showed a significantly improved normalized flux and a flux recovery ratio exceeding 80%, demonstrating excellent antifouling capability. Similar antifouling and high removal were also observed in humic acid separation. These compelling features highlight its potential for efficient water purification applications.