Methane oxy-steam reforming reaction: Performances of Ru/γ-Al2O3 catalysts loaded on structured cordierite monoliths

•A structured catalyst based on 1.5 wt.% Ru/γ-Al2O3 has been prepared.•The coating method combines solution combustion synthesis with wet impregnation.•The method is less time consuming and handling of powder is completely avoided.•The structured catalyst presented good thin coating and a high mechanical strength.•The coated monolith exhibited high catalytic activity towards CH4 OSR reaction.

The in situ deposition of 1.5 wt.% Ru/γ-Al2O3 catalytic layers on cordierite monoliths (400 cpsi, diameter 1 cm, length 1.5 cm), combining Solution Combustion Synthesis (SCS) with Wet Impregnation (WI), was addressed. First of all, the physicochemical properties of the catalyst at powder level were investigated by X-ray Diffraction (XRD), N2 adsorption (BET), and H2 chemisorption, while the morphology of final structured catalysts was evaluated by SEM analysis and mechanical strength tests by sonication. The catalytic activity towards methane Oxy-Steam Reforming (OSR) reaction was studied after the choice of the most suitable catalyst load, carrying out tests varying the temperature (500–800 °C), the oxygen-to-carbon ratio (O/C = 0.45–0.75, oxygen as moles), the steam-to-carbon ratio (S/C = 1.0–2.4), and the weight space velocity (WSV = 34,000–400,000 N ml gcat−1 h−1), in order to identify the optimum operative conditions. The results showed that a total catalytic layer load (active metal plus oxide carrier) equal to 6.5 mg cm−2 was enough to achieve excellent performances, while no substantial improvements were obtained at higher catalytic layer loads. Moreover, the coated Ru/γ-Al2O3 monolith exhibited a good catalytic activity towards the studied reaction also at considerably high WSV values (till 400,000 N ml gcat−1 h−1).