Dual-function Ni-based MOF for hydrogen storage and CO2 to carbonate cyclic catalysis

Abstract

International organizations highlight the need for technological progress with minimal environmental impact. In this context, we present Ni-URJC-3, a novel nickel-based metal–organic framework (MOF) with promising performance in H₂ and CO₂ adsorption and as a heterogeneous catalyst for cycloaddition reactions between epoxides and CO₂. The presence of azo groups (–NN–) in the organic linker enhances both adsorption and catalytic activity, acting as Lewis bases and outperforming other Ni-MOFs, even those with higher surface areas. Ni-URJC-3 exhibits an excellent H₂ gravimetric capacity of 3.7 wt% and a total volumetric uptake of 59.5 g L⁻¹, approaching the U.S. DOE target for hydrogen storage. This is attributed to both chemical factors, such as the electronic effects of azo groups, and physical ones, including the confinement effect within its microporous structure that enhances H₂ framework interactions. Regarding CO₂, the material shows a high adsorption enthalpy of 35.8 kJ mol⁻¹ and performs efficiently as a catalyst for the cycloaddition of CO₂ with various epoxides. These results demonstrate the potential of Ni-URJC-3 as a multifunctional MOF for environmental applications, particularly in gas storage and CO₂ transformation, contributing to the design of advanced materials aligned with sustainability goals.