Joule heating of CuO-ZnO/Ni foam catalyst for high H2 production and energy-saving of methanol decomposition: From the performance to mechanism
Xuechen Zhou, Limo He, C. Wang, Yufan Yang, Yanglin Chen, Song Hu, Sam Fong Yau Li, Yifei Sun, Sheng Su, Yi Wang, Jun Xiang
Abstract
Methanol, as a H 2 storage carrier, is a good option to tackle with the challenges of H 2 storage and transportation. To improve hydrogen production and reduce energy consumption, a new approach of electrified methanol decomposition (MD) by Joule heating was investigated in this work. The conductive metal skeleton catalysts were prepared using nickel foam (NF) as a catalyst support and employing a hydrothermal-impregnation method to load the Cu/Zn active components. The catalyst heats up rapidly upon energizing, and the heating rates reaches over 10 °C/s. The Joule heating method significantly promotes the methanol conversions of CuO-ZnO/NF, CuO/NF, and ZnO/NF. Methanol conversion over CuO-ZnO/NF at 300 °C under Joule heating is over 80 % higher than that of conventional external heating, while its energy consumption is only 29 % of that under external heating. As a result, methanol conversion per unit power in Joule heating condition increases by 5.6 times compared with that in external heating. The in/ex-situ characterizations reveal that the Joule heating of metal skeleton catalyst promotes the lattice oxygen release of NF skeleton and redox of Cu/Zn species, which generates an extra electrochemical effect on the reaction. This study of Joule heating provides a new strategy of converting methanol to H 2 in a more efficient, energy-saving, and flexible way, and has important application potential in hydrogen energy and chemical energy storage (“Power-to-X”).