Highly dispersed copper-based nanocomposite synthesis via spray pyrolysis: towards waste-to-hydrogen production through the water-gas shift reaction†

In this study, we synthesized a Cu–ZrCeO₂ catalyst using spray pyrolysis, which exhibited high activity, stability, and reusability at high temperatures. The catalyst was applied to a high-temperature water–gas shift reaction under practical conditions using waste-derived synthesis gas. Various reducible supports, including CeO₂, ZrO₂, TiO₂, ZrCeO₂, and TiCeO₂ were evaluated. Among these, the Cu–ZrCeO₂ (SPCZC) catalyst exhibited the highest activity and stability, attributed to its abundant oxygen defects, high Cu dispersion, and significant oxygen storage capacity. The SPCZC catalyst achieved 76% CO conversion and 100% CO₂ selectivity at 400 °C. It also maintained stable catalytic performance for 50 h, showing resistance to Cu sintering and preservation of the yolk–shell structure, indicating high reusability. A comprehensive deactivation study was conducted on the catalysts. Rapid Cu sintering was observed when CeO₂ was used as the sole support, leading to the breakdown of the yolk–shell structure. Catalysts supported on ZrO₂, TiO₂, and TiCeO₂ also experienced Cu sintering and carbon deposition, leading to deactivation.