Silica-Supported Copper (II) Oxide Cluster via Ball Milling Method for Catalytic Combustion of Ethyl Acetate

Highly dispersed CuO/SiO2 catalysts were successfully synthesized by a green process of ball milling (BM) under solvent-free and room temperature conditions. The structural evolution of CuO/SiO2 catalysts prepared by BM was elucidated by TG-DSC, XRD, FT-IR, and XPS characterizations. We found that the copper acetate precursor was dispersed over the layer of copper phyllosilicate which was formed by reacting between the copper acetate precursor and the silica support during the BM process. The copper phyllosilicate layer over the support might play an important role in the stabilization of the CuO cluster (2 catalyst exhibited the best catalytic activity for the catalytic combustion of ethyl acetate as it owned a highest active surface area of CuO among the CuO/SiO2 catalysts with different copper loadings

Ce_1−xSn_xO₂ Catalysts Prepared with Combustion Method for Catalytic Combustion of Ethyl Acetate

A series of Ce1−XSnXO2 (X = 0, 0.2, 0.3, 0.4, 0.5, 0.9, 1) catalysts were synthesized via the combustion method. The physical and chemical structures of the prepared catalysts were systematically characterized by XRD, BET, SEM, TEM, XPS, and TPR. The Ce1−XSnXO2 catalysts have higher catalytic activities than the mono-oxide catalysts, as there are synergistic effects between CeO2 and SnO2. The catalytic activities of the Ce1−XSnXO2 catalysts are dependent on the X for the catalytic combustion of ethyl acetate (EA). The Ce1−XSnXO2 (X 0.8Sn0.2O2 and Ce0.7Sn0.3O2 catalysts display the highest catalytic performance, with T50 = 190 °C and T90 = 210 °C. More importantly, the Ce0.8Sn0.2O2 catalyst exhibits superior thermal and catalytic activity stability. It is found that the Ce1−XSnXO2 catalysts form solid solutions, as the X is 4+ species to Sn2+ is significantly promoted by the CeO2, which is an important factor attributed to the high catalytic activities of the solid solution Ce1−XSnXO2 catalysts. The catalytic activities of the Ce1−XSnXO2 catalysts exhibit a strong correlation to the surface atomic areas of Ce3+ and Oα (VO). In other words, the higher surface atomic areas of Ce3+ and Oα (VO) are, the higher the catalytic activities will have

Safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine (RQ3013) given as the fourth booster following three doses of inactivated vaccines: a double-blinded, randomised, controlled, phase 3b trialResearch in context

Summary: Background: Heterologous vaccine schedules have been recommended to provide superior immunity and protection against emergent SARS-CoV-2 variants of concern. We aimed to evaluate the safety, immunogenicity, and efficacy of an mRNA COVID-19 vaccine RQ3013 compared with adenoviral vectored vaccine Ad5-nCoV and protein subunit vaccine ZF2001 as the fourth dose in adults primed with three doses of inactivated vaccines in China. Methods: We conducted a double-blinded, randomised, controlled, phase 3b trial among healthy Chinese adults at Lancang County, Yunnan, China. Adults who had received three doses of inactivated COVID-19 vaccines at least 6 months prior were randomly allocated (3:1:1) to receive heterologous boosters with RQ3013, Ad5-nCoV, or ZF2001. We assessed safety within 28 days post boost and the serum geometric mean titres (GMTs) of neutralising antibodies (NAbs) against the live SARS-CoV-2 omicron variant BA.5 on day 14 post-boost. We used Poisson regression to assess the vaccine efficacy against the first episode of virologically confirmed symptomatic COVID-19 occurring at least 7 days post boost. Subgroup analyses categorized by age and sex were also performed for safety and immunogenicity outcomes. This trial has been registered with the Chinese Clinical Trial Registry (ChiCTR2200065281) and is now complete. Findings: Between December 12 and December 18, 2022, a total of 1382 adults were screened, and 1250 were enrolled and randomly assigned to receive one dose of RQ3013 (n = 750), Ad5-nCoV (n = 250), or ZF2001 (n = 250). Although solicited adverse reactions within 28 days post boost were more frequent in the RQ3013 group (175 [23.3%]) compared to the control groups (24 [9.6%] in both the Ad5-nCOV and ZF2001 groups, P  0.05). On day 14 post-boost, RQ3013 (GMT 69.14, 95% CI 47.90–99.81) elicited 4.8-fold and 5.6-fold higher concentrations of NAbs against BA.5 than did Ad5-nCoV (14.37, 7.78–26.56) and ZF2001 (12.21, 5.13–29.06), respectively. On day 28 post-boost, RQ3013 demonstrated a relative efficacy of 62.2% (95% CI 13.7–83.1, P = 0.02) compared to Ad5-nCoV, and of 69.0% (33.5–85.7, P = 0.002) compared to ZF2001. Interpretation: The administrations of all the three heterologous boosters were well tolerated. The heterologous prime-boost regimen with RQ3013 elicited superior immune responses and demonstrated better protection against symptomatic SARS-CoV-2 infections compared with Ad5-nCoV or ZF2001, supporting the use of RQ3013 as a booster vaccination in adults. Funding: Yunnan Province Science and Technology Department (grant no.202302AA310047)