CeO₂ nanooctahedrons, nanorods, and nanocubes were prepared by the hydrothermal method and were then used as supports of Cu-based catalysts for the water-gas shift (WGS) reaction. The chemical and physical properties of these catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N₂ adsorption/desorption, UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H₂-TPR) and in situ diffuse reflectance infra-red fourier transform spectroscopy (DRIFTS) techniques. Characterization results indicate that the morphology of the CeO₂ supports, originating from the selective exposure of different crystal planes, has a distinct impact on the dispersion of Cu and the catalytic properties. The nanooctahedron CeO₂ catalyst (Cu-CeO₂-O) showed the best dispersion of Cu, the largest amount of moderate copper oxide, and the strongest Cu-support interaction. Consequently, the Cu-CeO₂-O catalyst exhibited the highest CO conversion at the temperature range of 150–250 °C when compared with the nanocube and nanorod Cu-CeO₂ catalysts. The optimized Cu content of the Cu-CeO₂-O catalysts is 10 wt % and the CO conversion reaches 91.3% at 300 °C. A distinctive profile assigned to the evolution of different types of carbonate species was observed in the 1000–1800 cm⁻¹ region of the in situ DRIFTS spectra and a particular type of carbonate species was identified as a potential key reaction intermediate at low temperature.

The direct chlorination of C–H bonds has received considerable attention in recent years. In this work, a metal-free protocol for hydrocarbon C–H bond chlorination with commercially available N-chlorosuccinimide (NCS) catalyzed by N-hydroxyphthalimide (NHPI) with 2,3-dicyano-5,6-dichlorobenzoquinone (DDQ) functioning as an external radical initiator is presented. Aliphatic and benzylic substituents and also heteroaromatic ones were found to be well tolerated. Both the experiments and theoretical analysis indicate that the reaction goes through a process wherein NHPI functions as a catalyst rather than as an initiator. On the other hand, the hydrogen abstraction of the C–H bond conducted by a PINO species rather than the highly reactive N-centered radicals rationalizes the high chemoselectivity of the monochlorination obtained by this protocol as the latter is reactive towards the C(sp³)–H bonds of the monochlorides. The present results could hold promise for further development of a nitroxy-radical system for the highly selective functionalization of the aliphatic and benzylic hydrocarbon C–H.

Metal-containing ZSM-5 zeolites, denoted as M/ZSM-5 (M = Ga, Zn, and La), were prepared by an in situ synthetic method. The structural, textural, and surface acid properties of M/ZSM-5 were characterized by XRD, N₂ adsorption-desorption, NH₃-TPD, and FT-IR. The catalyst pore size and the distribution of strong acid and weak acid were affected by the introduction of metal. Considering the methanol-to-aromatics model reaction, the catalytic performance of these samples was investigated in a fixed bed reactor under the conditions of 450 °C and a liquid weight hourly space velocity (WHSV) of 5 h^-1. The results indicated that the Zn/ZSM-5 molecular sieve was most beneficial to aromatization; the relationship between the change of B/L caused by Zn content and aromatics selectivity was further studied. When the B/L value decreased, the selectivity of aromatics showed an initial increase and then a decrease. The B/L value was optimal, and the aromatics yield was the highest when the Zn loading was 0.35%.

The oxidation of benzene to phenol (BTOP) with N₂O as the oxidant has been studied with a variety of Fe/ZSM-5 catalysts. The literature has conclusively proven that Fe²⁺ sites are the active sites. However, some studies have suggested that the Lewis acidic sites (LAS) are responsible for the generation of the active chemisorbed oxygen. Nevertheless, there is no clear relationship between the LAS and the N₂O selectivity to phenol. In an effort to elucidate the effects of LAS on BTOP with various ZSM-5 catalysts, we investigated the initial N₂O selectivity to phenol. Here we show that the initial N₂O selectivity to phenol is negative with the amount of LAS over a certain range. The catalyst H-ZSM-5-ST (H-ZSM-5 treated with water vapor) showed a remarkable initial N₂O selectivity to phenol as high as 95.9% with a 0.021 mmol g⁻¹ LAS concentration on the surface of the catalyst, while the Fe/ZSM-5 catalyst demonstrated the lowest initial N₂O selectivity to phenol (11.7%) with the highest LAS concentration (0.137 mmol g⁻¹). Another remarkable feature is that steaming was more effective than Fe ion exchange and high temperature calcining. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N₂-adsorption-desorption, UV-vis, NH₃-TPD and pyridine Fourier transform infrared (FT-IR) techniques. Our results demonstrate how the concentration of LAS is likely to affect the initial N₂O selectivity to phenol within a certain range (0.021–0.137 mmol g⁻¹). This research has demonstrated the synergy between the active Fe²⁺ sites and LAS.