Energy-Efficient Co-production of Benzoquinone and H2 Using Waste Phenol in a Hybrid Alkali/Acid Flow Cell.

In both the manufacturing and chemical industries, benzoquinone is a crucial chemical product. A perfect and economical method for making benzoquinone is the electrochemical oxidation of phenol, thanks to the traditional thermal catalytic oxidation of phenol process requires high cost, serious pollution and harsh reaction conditions. Here, a unique heterostructure electrocatalyst on nickel foam (NF) consisting of nickel sulfide and nickel oxide (Ni9S8-Ni15O16/NF) was produced, and this catalyst exhibited a low overpotential (1.35 V vs. RHE) and prominent selectivity (99 %) for electrochemical phenol oxidation reaction (EOP). Ni9S8-Ni15O16/NF is beneficial for lowering the reaction energy barrier and boosting reactivity in the EOP process according to density functional theory (DFT) calculations. Additionally, an alkali/acid hybrid flow cell was successfully established by connecting Ni9S8-Ni15O16/NF and commercial RuIr/Ti in series to catalyze phenol oxidation in an alkaline medium and hydrogen evolution in an acid medium, respectively. A cell voltage of only 0.60 V was applied to produce a current density of 10 mA cm-2. Meanwhile, the system continued to operate at 0.90 V for 12 days, showing remarkable long-term stability. The unique configuration of the acid-base hybrid flow cell electrolyzer provides valuable guidance for the efficient and environmentally friendly electrooxidation of phenol to benzoquinone.

Probable Evidence of Aerosol Transmission of SARS-COV-2 in a COVID-19 Outbreak of a High-Rise Building.

Although it is well established that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be transmitted through aerosols, the mode of long-range aerosol transmission in high-rise buildings remains unclear. In this study, we analyzed an outbreak of coronavirus disease 2019 (COVID-19) that occurred in a high-rise building in China. Our objective was to investigate the plausibility of aerosol transmission of SARS-CoV-2 by testing relevant environmental variables and measuring the dispersion of a tracer gas in the drainage system of the building. The outbreak involved 7 infected families, of which 6 were from vertically aligned flats on different floors. Environmenìtal data revealed that 3 families' bathrooms were contaminated by SARS-CoV-2. In our tracer experiment, we injected tracer gas (CO2) into the dry floor drains and into water-filled toilets in the index case' s bathroom. Our findings showed that the gas could travel through vertical pipes by the dry floor drains, but not through the water of the toilets. This indicates that dry floor drains might facilitate the transmission of viral aerosols through the sewage system. On the basis of circumstantial evidence, long-range aerosol transmission may have contributed to the community outbreak of COVID-19 in this high-rise building. The vertical transmission of diseases through aerosols in high-rise buildings demands urgent attention.

High-Performance Na-CH3ONa/γ-Al2O3 Catalysts for High-Efficiency Conversion of Phenols to Ethers.

An efficient alkaline catalyst with a porous structure (Na-CH3ONa/γ-Al2O3) was prepared by the melting method. The wastewater from the semicoke plant (WWSCP) was extracted multiple times with isometric dimethyl carbonate (DMC)-cyclohexane mixed solvent at room temperature to obtain an organic phase (OP) with a high concentration of phenols. Ether (OPCP) was obtained by catalytic conversion of OP over catalyst Na-CH3ONa/γ-Al2O3 at 210 °C and with a reaction time of 2.5 h. Both OP and OPCP were analyzed with a gas chromatograph/mass spectrometer (GC/MS) and a quadrupole Exactive Orbitrap mass spectrometer (QPEOTMS). The results showed that only DMC, phenol, o-cresol, and other monohydric phenols were detected in OP, and only other saturated ethers such as anisole and O-methylanisole were detected in OPCP. Through the study of the catalytic conversion of the WWSCP-related model compound, it was found that Na-CH3ONa/γ-Al2O3 could effectively activate (deprotonate) phenol into phenate, and the strong nucleophilic oxyanion of phenate would attack the methyl carbon and carbonyl carbon on DMC to obtain methyl and methoxy groups. Thereby, phenate can be combined with methyl and methoxy groups to acquire the product anisole. In addition, the catalyst Na-CH3ONa/γ-Al2O3 was found to still have high catalytic activity after 10 repeated cycles. It was speculated that this was related to the abundant microporous and mesoporous structure of the catalyst Na-CH3ONa/γ-Al2O3.

[Simultaneous determination of 54 elements in human whole blood by inductively coupled plasma mass spectrometry].

OBJECTIVE: To establish a method for simultaneous determination of 54 elements in whole blood by inductively coupled plasma mass spectrometry (ICP-MS). METHODS: The whole blood sample was digested with nitric acid and hydrogen peroxide in a water bath at 90°C, and then analyzed by ICP-MS with 0.1% ethanol as an matrix-matching agent. RESULTS: A good linear relationship was achieved when the concentrations of the 54 elements in whole blood were in the standard range (all r >0.999). The recovery rate of the sample plus the standard was between 80% and 106%, and the relative standard deviation was less than 5%. The standard material of whole blood was determined and the results met the certification requirements. CONCLUSION: The method is simple, rapid, sensitive, and accurate. It is applicable for simultaneous determination of multi-elements in a large number of whole blood samples.