Nonoxidative coupling of ethane with gold loaded photocatalysts

Direct and continuous conversion of ethane to yield n-butane and hydrogen at near room temperature (ca. 320 K) was examined with gold loaded gallium oxide and titanium dioxide photocatalysts without the aid of any oxidant in a flow reactor. A Ga2O3 photocatalyst produced n-butane and ethene as well as hydrogen with an almost stoichiometric ratio of products from ethane. Loading Au on the Ga2O3 sample gave a 12 times higher production rate of n-butane such as 0.65 mu mol h(-1) with a high selectivity of 89%. Although a bare TiO2 sample showed very low yield due to poor reduction resistance, the addition of an Au cocatalyst drastically improved the photocatalytic performance of the TiO2 sample, i.e., the Au(0.2)/TiO2 sample produced n-butane and ethene continuously at least for 5 h, where the production rate of n-butane, the n-butane selectivity, and the apparent quantum efficiency (AQE) for n-butane formation were 0.92 mu mol h(-1), 92%, and 0.02%, respectively. The reaction mechanism of n-butane formation as the main reaction was proposed to be the photocatalytic nonoxidative coupling of ethane (NOCE), which is similar to the photocatalytic nonoxidative coupling of methane (NOCM).

Automated summary

This study investigated the direct conversion of ethane to n-butane and hydrogen using gold loaded gallium oxide and titanium dioxide photocatalysts. The Ga2O3 photocatalyst produced n-butane, ethene, and hydrogen with a nearly stoichiometric ratio of products. The addition of gold to the Ga2O3 sample significantly increased the production rate of n-butane, while the addition of gold cocatalyst improved the photocatalytic performance of the TiO2 sample.