Low-temperature synthesis of α-alumina nanosheets on microfibrous-structured Al-fibers for Pd-catalyzed CO oxidative coupling to dimethyl oxalate

Chunzheng Wang (1) , Weisong Xu (1) , Zhengxing Qin (1) , Xinmei Liu (1) , Svetlana Mintova (2, 1)

1 China University of Petroleum
2 LCS - Laboratoire catalyse et spectrochimie

We reported the low-temperature synthesis of -Al2O3 nanosheets on the microfibrous-structured Alfibers at 800 º C. The boehmite (AlOOH) nanosheets were initially formed on the Al-fibers through in situ endogenous growth. Then the AlOOH/Al-fibers was transformed to the -Al2O3/Al-fibers composite at 800 º C by a single heating step. The low-temperature phase transformation was tentatively attributed to the Al metal in the AlOOH/Al-fibers. Palladium was then dispersed on the -Al2O3/Alfibers composite, and the resulting Pd/-Al2O3/Al-fibers catalyst was examined in the strongly exothermic CO oxidative coupling to dimethyl oxalate (DMO) reaction. High CO conversion of 58 % and DMO selectivity of 95 % were obtained and maintained for at least 150 h using a feedgas of CH3ONO / CO / N2 (1 / 1.4 / 7.6, mole) at 150 º C with a gas hourly space velocity of 20000 mL g 1 h 1. Computational fluid dynamics calculations and experimental results indicated that the Pd/-Al2O3/Al-fibers catalyst remarkably decreased the hot-spot temperature of catalyst bed due to its enhanced thermal conductivity.

Mots clés: Structured catalyst; Alpha alumina; Nanosheet; Phase transformation; Aluminum fiber; Dimethyl oxalate

Domaines: Catalyse; Chimie organique

Chunzheng Wang, Weisong Xu, Zhengxing Qin, Xinmei Liu, Svetlana Mintova. Low-temperature synthesis of α-alumina nanosheets on microfibrous-structured Al-fibers for Pd-catalyzed CO oxidative coupling to dimethyl oxalate. Catalysis Today, 2020, 354, pp.158-166. ⟨10.1016/j.cattod.2019.03.005⟩. ⟨hal-02409902⟩