Bimetallic Copper–Cerium-Based Metal–Organic Frameworks for Selective Carbon Dioxide Capture
Deshetti Jampaiah, Daksh Shah, Anastasios Chalkidis, Pallavi Saini, Ravichandar Babarao, Hamidreza Arandiyan, Suresh K. Bhargava
Abstract
Metal–organic frameworks (MOFs) are highly regarded as valuable adsorbent materials in materials science, particularly in the field of CO 2 capture. While numerous single-metal-based MOFs have demonstrated exceptional CO 2 adsorption capabilities, recent advancements have explored the potential of bimetallic MOFs for enhanced performance. In this study, a CuCe-BTC MOF was synthesized through a straightforward hydrothermal method, and its improved properties, such as high surface area, smaller pore size, and larger pore volume, were compared with those of the bare Ce-BTC. The impact of the Cu/Ce ratio (1:4, 1:2, 1:1, and 3:2) was systematically investigated to understand how adding a second metal influences the CO 2 adsorption performance of the Ce-BTC MOF. Various characterization techniques, including scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and N 2 BET surface area analysis, were employed to assess the physical and chemical properties of the bare Ce-BTC and CuCe-BTC samples. Notably, CuCe-BTC-1:2 exhibited superior surface area (133 m 2 g –1 ), small pore size (3.3 nm), and large pore volume (0.14 cm 3 g –1 ) compared to the monometallic Ce-BTC. Furthermore, CuCe-BTC-1:2 demonstrated a superior CO 2 adsorption capacity (0.74 mmol g –1 ), long-term stability, and good CO 2 /N 2 selectivity. This research provides valuable insights into the design of metal-BTC frameworks and elucidates how introducing a second metal enhances the properties of the monometallic Ce-BTC-MOF, leading to improved CO 2 capture performance.