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Background: Selective catalytic reduction of nitrogen oxides with ammonia (NH3‐SCR) is an effective method for the nitrogen oxides (NOx) removal. This study aimed to develop a highly efficient NH3‐SCR catalyst using the naturally available Montmonrillonite (Mt) clay as the catalyst support. Results: Mt was processed into PILC by Al/Zr intercalations, impregnated with MnCe mixed active components and loaded with transition metals to achieve X‐AlZr‐PILC‐MnCe (X = V, W, Co or Mo) catalysts. The optimized Mo‐AlZr‐PILC‐MnCe showed the best NH3‐SCR performance with a NO conversion rate of nearly 100% in the temperature range of 240–300 °C, and N2 selectivity of above 85% in the range of 140–300 °C. Conclusions: The catalysts were characterized by SEM, BET, XRD, XPS, H2‐TPR, NH3‐TPD to define the relationships between structure, chemical properties and catalytic activity. The enhanced catalytic performance of Mo‐AlZr‐PILC‐MnCe was mainly owing to the increased acidity and better redox ability. In situ DRIFT studies indicated the deposition of Mo changed the reaction from the E‐R to the L‐H mechanism. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Electro-generation of NaOH and H2SO4 with organic compound-free Na2SO4 wastewater has been known for many years, but actually, lots of Na2SO4 wastewater contains organic pollutants, such as black liquor, dyeing and sulphonating wastewater etc., therefore, there is a strong demand for investigations on performance and effect of the organic pollutants in electrochemically splitting Na2SO4 into H2SO4 and NaOH from these wastewaters. RESULTS Co-electrolysis of Na2SO4 (1.13 mol L−1) and AO7 (50 ∼ 500 mg L−1) was investigated in a diaphragm cell with IrO2-coated Ti electrodes. It was found that the concentrations of the resulting NaOH and H2SO4 could remain at about 0.73 mol L−1 and 0.36 mol L−1, respectively, although the COD removal was increased from 50.3 mg L−1 to 166.3 mg L−1 with the increase of AO7 concentration, for 120 min. CONCLUSION In a diaphragm cell with IrO2-coated Ti electrodes, NaOH and H2SO4 could be effectively generated, and simultaneously, AO7 could also be degraded for the wastewater containing Na2SO4 and AO7. Interestingly, the electro-generation of NaOH and H2SO4 was not significantly affected by the occurrence and degradation of AO7 in the range 0-500 mg L−1. The phenomenon of constant acid-base yield contributed to the independence of the main acid-generating reactions on the electro-oxidation of AO7. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Discovery of the nanometer material-mediated piezoelectric effect has aroused interest in research into harnessing low-frequency vibration energy, because a little vibration energy, even muscle-movement, can generate electrical energy. Recently, much attention has focused on developing new processes of pollutant degradation using in situ application of piezo-generated electrical energy. RESULTS It was found that the piezoelectric degradation of AO7 could be enhanced by adding ferrous ions. For example, 24.3%, 16.9% and 7.8% degradation of AO7, phenol and 4-chlorophenol, respectively, was observed in a 30 min piezo-process. Meanwhile, it was also found that H2O2 was generated in situ during the piezoelectric process. The maximum concentration of H2O2 reached 5.3 µmol L−1. It was identified that the enhancement effect of ferrous ions originated from a H2O2-related Fenton reaction. CONCLUSION The finding of in situ piezo-generated H2O2 and the piezo-Fenton effect led to better understanding of the BaTiO3-mediated piezo-degradation of organic pollutants. It provides a new clue to developing an efficient piezo-process for the degradation of organic pollutants, although the mechanism of piezo-generating H2O2 is still under investigation. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Chemical mechanical polishing (CMP) offers a promising pathway to smooth third-generation semiconductors. However, it is still a challenge to reduce the use of additional oxidants or/and energy in current CMP processes. Here, a new and green atomically smoothing method: Piezocatalytic-CMP (Piezo-CMP) is reported. Investigation shows that the Piezo-CMP based on tetragonal BaTiO 3 (t-BT) can polish the rough surface of a reaction sintering SiC (RS-SiC) to the ultra-smooth surface with an average surface roughness (Ra) of 0.45 nm and the rough surface of a single-crystal 4H-SiC to the atomic planarization Si and C surfaces with Ra of 0.120 and 0.157 nm, respectively. In these processes, t-BT plays a dual role of piezocatalyst and abrasive. That is, it piezo-catalytically generates in-situ active oxygen species to selectively oxidize protruding sites of SiC surface, yielding soft SiO 2 , and subsequently, it acts as a usual abrasive to mechanically remove these SiO 2 . This mechanism is further confirmed by density functional theory (DFT) calculation and molecular simulation. In this process, piezocatalytic oxidation is driven only by the original pressure and friction force of a conventional polishing process, thus, the piezo-CMP process do not require any additional oxidant and energy, being a green and effective polishing method., (© 2023 Wiley‐VCH GmbH.)