Guan-Fu Pan

CVD synthesis of Cu2O films for catalytic application

Pure Cu2O was synthesized at 270 °C by pulsed-spray evaporation chemical vapor deposition. The results indicate that Cu2O is effective for the complete oxidation of VOCs with good reusability and reproducibility. The lattice and adsorbed oxygen as well as the hollow ball-like geometry are dedicated to the catalytic processes.

Tailored synthesis of CoOX thin films for catalytic application

Cobalt oxide thin films were systematically synthesized on an inert carrier by pulsed-spray evaporation chemical vapor deposition (PSE-CVD). The effect of substrate temperature on the structure, morphology and surface composition of the prepared films was investigated by XRD, FTIR, SEM and XPS spectroscopies. An in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) and a gas chromatograph (GC) were involved to identify the surface and gaseous species occurring in the total oxidation of propene as a representative of VOCs, respectively. The structural analysis indicated that the obtained thin films transformed from CoO to pure Co3O4 spinel as the temperature rose from 350 to 450 °C. A homogeneous grain distribution was observed. For all samples, oxygen was mainly composed of lattice oxygen and adsorbed oxygen constituted a minor proportion. The catalytic tests showed that all the thin films exhibited competitive performances to those of noble metals. According to the observed adsorption peaks of propene at low-temperature and transformation of CoO–Co3O4 from the in situ DRIFTS spectra, a combined redox and L–H mechanism was proposed for the catalytic oxidation of propene over cobalt oxide films. The porous structure and adsorbed oxygen on the film surface may well contribute to the catalytic oxidation of propene.

CVD‐Made Spinels: Synthesis, Characterization and Applications for Clean Energy

To reduce emissions and protect environment from pollution caused by volatile organic compounds (VOCs) and CO, catalytic oxidation can be applied as an efficient and promising technique. This review provides a novel and facile strategy to synthesize spinel-type and non-spinel-type transition metal oxides (TMOs). Specifically, single (Co3O4, α-Fe2O3, Mn3O4, CuO, Cu2O and Cr2O3) and binary (Co3-xCuxO4, Co3-xMnxO4 and Co3-xFexO4) TMOs have been prepared using pulsed spray evaporation chemical vapor deposition approach (PSE-CVD). PSE-CVD offers several advantages over conventional methods, such as relatively low cost, simplicity and high throughput, which makes it a promising strategy. Moreover, the PSE delivery system allows using less stable precursors and permits improving the reproducibility of the film properties with tailored compositions. The above listed TMOs prepared by PSE-CVD were successfully tested as catalysts toward the complete oxidation of some real fuels such as CO, C2H2, C3H6, n-C4H8 and C2H6O as representatives of VOCs and industrial exhaust streams. The active TMOs explored in this review could be potential catalysts candidates in one of the research areas that are currently under scrutiny, as the battle for the future of energy and environment involves the generation and application of clean energy.

Bituminous Coal Combustion with New Insights

As one of the most important primary energy, bituminous coal has been widely applied in many fields. The combustion studies of bituminous coal have attracted a lot of attention due to the releases of hazardous emissions. This work focuses on the investigation of combustion characteristics of Shenmu bituminous pulverized coal as a representative bituminous coal in China with a combined TG-MS-FTIR system by considering the effect of particle size, heating rate, and the total flow rate. The combustion products were accurately quantified by normalization and numerical analysis of MS results. The results indicate that the decrease of the particle size, heating rate, and the total flow rate result in lower ignition and burnout temperatures. The activation energy tends to be lower with smaller particle size, faster heating rate, and lower total flow rate. The MS and FTIR results demonstrate that lower concentrations of different products, such as NO, NO2, HCN, CH4, and SO2, were produced with smaller particle size, slower heating rate, and lower total flow rate. This work will guide to understand the combustion kinetics of pulverized coals and be beneficial to control the formation of pollutants.