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This work investigated the effect of the defect structure referred to as Ti3+ present in titania support of supported titania on characteristics and activity of the Co/TiO2 catalyst. Titania supports were prepared by sol−gel and then calcined under N2 plus increasing the amount of O2 to change the surface defect concentration. The surface defect of titania support was increased by increasing the oxygen percent in feed during the calcination process. This defect was monitored using the CO2-temperature program reduction (CO2-TPD) and electron spin resonance (ESR). Cobalt was impregnated onto titania supports containing different defect structures. XRD, SEM-EDX, TPR, and H2-chemisorption were used to characterize Co/TiO2. It was found that dispersion of cobalt and reducibility increased with the amount of surface defect present. Based on high dispersion and reducibility results this catalyst showed a high conversion for methanation without changing CH4 selectivity.

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Recently, the interest in ethanol production from renewable natural sources in Thailand has been receiving much attention as an alternative form of energy. The low-cost accessibility of ethanol has been seen as an interesting topic, leading to the extensive study of the formation of distinct chemicals, such as ethylene, diethyl ether, acetaldehyde, and ethyl acetate, starting from ethanol as a raw material. In this paper, ethanol dehydrogenation to acetaldehyde in a one-step reaction was investigated by using commercial activated carbon with four different metal-doped catalysts. The reaction was conducted in a packed-bed micro-tubular reactor under a temperature range of 250–400 °C. The best results were found by using the copper doped on an activated carbon catalyst. Under this specified condition, ethanol conversion of 65.3% with acetaldehyde selectivity of 96.3% at 350 °C was achieved. This was probably due to the optimal acidity of copper doped on the activated carbon catalyst, as proven by the temperature-programmed desorption of ammonia (NH3-TPD). In addition, the other three catalyst samples (activated carbon, ceria, and cobalt doped on activated carbon) also favored high selectivity to acetaldehyde (>90%). In contrast, the nickel-doped catalyst was found to be suitable for ethylene production at an operating temperature of 350 °C.