Work

Ruthenium-based MOF catalysts for methanation of CO2 derivatives

Year: 2025

Type: article

Abstract: Mitigating climate change is one of the biggest challenges of today's society. The most direct way to achieve this goal is to capture and use CO 2 as a source of energy and chemicals. This work, inspired by previous publications focused on homogeneous catalysis, proposes the transformation of the easy-to-prepare CO 2 derivatives dialkylureas into C1 chemicals using Ru-MOFs as heterogeneous catalysts. This choice is due to (i) the well-known ability of Ru to catalyze hydrogenation reactions and (ii) that Ru-complexes were the pioneer homogenous catalyst in converting CO 2 into an added-value C1 chemical, methanol. Apart from the already reported MOF Ru-HKUST-1, we have prepared a new Ru-MOF material, denoted Ru-BTC, analogous to the semiamorphous Fe-BTC. It has been found by XAS that Ru-BTC and Ru-HKUST-1 have different metal environment and oxidation states: only 3+ in Ru-BTC, a 50:50 mixture of 2+ and 3+ in Ru-HKUST-1. Both Ru-MOFs catalyzed the hydrogenation of N,N’-dimethylurea under relatively mild conditions, giving methane as the main product. Ru-BTC was particularly efficient: 67 % conversion and 96 % selectivity to CH 4 at 150 ºC and 30 bars of H 2 using a Ru/dimethylurea weight ratio of 1 %. Ru-MOFs were also able to transform CO 2 into CH 4 , again being Ru-BTC the most effective catalyst, but giving much poorer selectivity to CH 4 . Ru-MOFs, particularly Ru-BTC, were damaged under reaction conditions, but no significant Ru leaching was observed.

Source: Journal of CO2 Utilization

DOI: 10.1016/j.jcou.2025.103127