Modulating the Oxidation State of Titanium via Dual Anions Substitution for Efficient N2 Electroreduction.

The electrocatalytic nitrogen reduction reaction (NRR) is a promising approach for renewable ammonia synthesis but remains significantly challenging due to the low yield and poor selectivity. Herein, a facile N and S dual anions substitution strategy is developed to tune the Ti oxidation states of TiO2 nanohybrid catalyst (NS-TiO2 /C), in which anatase TiO2 nanoplates with dense Ti3+ active sites are uniformly dispersed on porous carbon derived from 2D Ti3 C2 Tx nanosheets. The catalyst NS-TiO2 /C exhibits a superior ambient NRR efficiency with an NH3 yield rate of 19.97 µg h-1 mg-1cat and Faradaic efficiency of 25.49% and is coupled with a remarkable 50 h long-term stability at -0.25 V versus RHE. Both experimental and theoretical results reveal that the N and S dual-substitution effectively regulate the Ti oxidation state and electronical properties of the NS-TiO2 /C via simultaneously forming interstitial and substitutional TiS and TiN bonds in the anatase TiO2 lattice, inducing oxygen vacancies and dense Ti3+ active species as well as better electronic conductivity, which substantially facilitates N2 chemisorption and activation, and reduces the energy barrier of the rate-determining step, thereby essentially boosting NRR efficiency. This work provides a valuable approach to the rational design of advanced materials by modulating oxidation states for efficient electrocatalysis.

POSTOPERATIVE CHANGES AND PROGNOSTIC FACTORS OF VISUAL ACUITY, METAMORPHOPSIA, AND ANISEIKONIA AFTER VITRECTOMY FOR EPIRETINAL MEMBRANE.

PURPOSE: To investigate postoperative changes and prognostic factors of visual impairment after vitrectomy for unilateral epiretinal membrane. METHODS: A prospective observational study on 45 eyes from 45 patients with unilateral idiopathic epiretinal membrane who underwent vitrectomy. Visual parameters (best-corrected visual acuity, metamorphopsia using M-CHARTS, and aniseikonia using the New Aniseikonia Test) and spectral domain optical coherence tomography parameters (macular retinal layer thickness and microstructure of the outer retina) were measured preoperatively and 6 and 12 months postoperatively. Statistical analyses included linear mixed-effects models for the longitudinal changes and prognostic factors of visual parameters. RESULTS: Best-corrected visual acuity and horizontal metamorphopsia improved significantly from 6 months after surgery (P < 0.001), whereas aniseikonia decreased significantly only at 12 months (P = 0.015). Vertical metamorphopsia remained unchanged. Preoperative inner nuclear layer thickness was significantly correlated with preoperative metamorphopsia. Besides baseline values, best-corrected visual acuity had no significant prognostic factors, but preoperative ellipsoid zone disruption had a negative direction of association with postoperative metamorphopsia (coefficients: -0.37 and -0.62, P = 0.015 and 0.006 for horizontal and vertical metamorphopsia, respectively), and preoperative horizontal metamorphopsia had a positive direction of association with postoperative aniseikonia (coefficient: 1.77, P = 0.002). CONCLUSION: After vitrectomy, postoperative changes and prognostic factors for unilateral epiretinal membrane differed for best-corrected visual acuity, metamorphopsia, and aniseikonia.

Dehydrogenative Coupling of Alkanes and Benzene Enhanced by Slurry-Phase Interparticle Hydrogen Transfer.

The dehydrogenative coupling reaction of alkanes and benzene has attracted attention as a method of direct conversion of alkanes to raw materials for useful chemical products. Here, we report the first combined catalyst system composed of hydrotalcite-supported palladium and solid acid aluminum-exchanged montmorillonite for the direct alkylation of benzene promoted by slurry-phase interparticle hydrogen transfer at 150 °C. The combination of the two catalytic particles showed excellent activity and achieved the maximum benzene conversion of 21% and target product selectivity of 84% in the reaction of n-heptane and benzene. Our results, thus, provide a feasible strategy to design efficient liquid-phase reaction systems employing simple physical mixing of two catalytic particles.

Direct Alkylation of Benzene at Lower Temperatures in the Liquid Phase: Catalysis by Montmorillonites as Noble-Metal-Free Solid Acids.

Alkylated benzenes are widely used as raw materials for the production of a variety of chemical compounds. Conventionally, they are obtained by the Friedel-Crafts reaction between alkyl halides and benzene. In this study, the synthesis of halogen-free alkylated benzenes was made possible by the direct alkylation of benzene with alkanes using montmorillonites as noble-metal-free solid acid catalysts. The direct alkylation of benzene with n-heptane was performed at 150 °C. Aluminum-exchanged montmorillonite showed the highest yield of the target C-7 alkylated products (Ph-C7) compared with other homogeneous and heterogeneous acid catalysts: 1.8 % conversion of benzene with 58 % selectivity in 16 h. The montmorillonite catalyst system was applied to other linear and cyclic alkanes to give the corresponding alkylated products with good selectivities.