A highly active and hydrothermal-resistant Cu/ZnO@NC catalyst for aqueous phase reforming of methanol to hydrogen

Abstract

Aqueous-phase reforming (APR) of methanol provides a safe way to store and transport hydrogen by in situ production of H2. It remains, however, a challenge to develop an efficient and hydrothermal-stable non-noble-metal catalyst. Herein, a robust Cu/ZnO@NC catalyst is successfully constructed by encapsulating Cu/ZnO species in nitrogen-doped carbon (NC), using ZIF-8 as precursor. It is demonstrated that the activity for APR of methanol increases exponentially with rise of catalyst wettability. With good wettability, a high hydrogen releasing rate of 146.9 μmol·gcat−1·s−1 is achieved on the 27%Cu/ZnO@NC catalyst at 230 °C, about four times higher than that of a traditional 29%Cu/ZnO catalyst, and surprisingly comparable to a commercial Pt/C catalyst. Notably, Cu/ZnO@NC also shows excellent stability, as the NC coating protects ZnO from hydrolyzing and prevents aggregation of Cu nanoparticle largely in the severe aqueous-phase-reaction conditions. This work develops a convenient method to prepare efficient and hydrothermal-stable catalyst with commercial potential.