Dry reforming of methane using cordierite monoliths with immobilized Ni–Ce catalysts

Powdered Ni-based catalysts exhibit good performance in the dry reforming of methane (DRM); however, they suffer from limited industrial applicability. Structured monolithic catalysts can overcome these limitations. In this sense, we present the synthesis of Ni–Ce mixed oxide-type catalysts immobilized in cordierite monoliths using a simple coprecipitation method and slurry coating without additives using hydrotalcite precursors for catalyst preparation. Our research explores the role of Ce (0–7 % w/w) as a promoter and the impact of immobilizing mixed oxides (MO) within cordierite monoliths on the physicochemical properties and catalytic performance of non-previously H2-reduced materials in DRM at 700 °C. Our findings reveal the favorable impact of Ce on the physicochemical properties of the catalyst in both the powder and monoliths, including smaller crystallite sizes, enhanced CO2 adsorption, and reducibility with higher Ce loading. The immobilized mixed oxide (MO) maintained its crystalline structure and formed stable, uniform layers with thicknesses below 10 μm in the monoliths. The powders exhibited stable conversions of 70–80% for CH4 and 66–75% for CO2, whereas the monoliths showed conversions of 85–90% for CH4 and 80–90% for CO2 at 700 °C and 94,680 mL·gcat−1·h−1. A higher catalyst loading in the monoliths did not result in detrimental catalytic conversion. On average, the monoliths had a higher H2/CO ratio (1.25–1.5) compared to the powders (1–1.25), which may explain the increased coke formation rate in the monoliths from methane cracking. Ce improved the stability and reduced coke formation, particularly when the space velocity was lower. This research highlights the significant advantages of immobilizing mixed oxides (MO) in monolithic structures, making them highly promising for potential industrial scale-up. Their stability, recoverability, elimination of high-cost H2 reduction, and reusability in subsequent catalytic tests contributed to their favorable characteristics.