Control of Ni/Ce1-xMxOy Catalyst Properties Via the Selection of Dopant M = Gd, La, Mg. Part 2. Catalytic Activity

Abstract

To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2–15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1–0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200–700 °C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10–15% yield of H2 at 700 °C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tо 300 °С, hydrogen yield increases from 25 to 60%, the inhibition of С2-С3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 °C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen.

Catalytic Hydrogen Generation and Use for Production of Fuels

“…Note that the influence of the reaction conditions (500-700 C, C 2 H 5 OH:H 2 O = 1-4, C 2 H 5 OH:O 2 = 0.2-0.8) was preliminarily studied, and the optimal molar ratio of the reagents for the maximum hydrogen yield was selected. In contrast to our previous [41,57], there was no reduction of catalysts before catalytic activity tests. In this the active centers will be formed directly under the reaction conditions.…”

“…Both homogeneous and heterogeneous catalytic systems have been explored, but the advantages of heterogeneous catalysts make these systems preferred from a practical point of view. There is vast literature reported on the hydrolytic dehydrogenation of AB, highlighting those contributions made by Yamashita et al [46][47][48][49][50][51][52][53][54], Özkar et al [55][56][57][58], and Xu et al [44,[59][60][61][62].…”