Modulating length of metal-organic framework by seed self-sacrificial strategy to fabricate Cu2O/MOF composite materials with high C2 selectivity

A seed self-sacrificial strategy was proposed to prepare Cu 2 O/MOF composites with tunable MOF lengths. • The synthesized MOF exhibited unique CO 2 adsorption capacity , with an optimal value of 97.50 cm 3 /g. • Tuning outer MOF length modulated CO 2 adsorption, enabling selective control over C 1 and C 2 conversion. • When the outer MOF layer reached 500 nm, Cu 2 O/MOF-2 achieved optimal C 2 selectivity with an FE of 81.43% and 16 h stability. • In situ FTIR and DFT showed that MOF-enhanced CO 2 adsorption raised *CO coverage on Cu 2 O/MOF, lowering C 2 formation barrier. In the electrocatalytic process of Carbon dioxide reduction reaction (CO 2 RR), one of the challenges faced by copper (Cu)-based MOF catalysts is insufficient structural stability, which leads to low utilization of active sites and reduced product selectivity. This study proposed a seed self-sacrifice strategy to fabricate Cu 2 O/MOF composite materials with tunable metal-organic framework (MOF) lengths, where cuprous oxide (Cu 2 O) serves as a metal-source seed to support the growth of the outer MOF. By regulating the length of the outer MOF material, the degree of CO 2 concentration can be modulated, thereby enabling precise control over the conversion rates of C 1 and C 2 products. In particular, when the length of the outer MOF is approximately 500 nm, Cu 2 O/MOF-2 achieves the highest selectivity for C₂ products, reaching 81.43%. In-situ Fourier-transform infrared spectroscopy measurements and density functional theory calculations reveal that the MOF with an appropriate length exhibits optimal adsorption effects for CO 2 . This increases the coverage of the *CO adsorption layer at the Cu 2 O/MOF interface, thereby lowering the energy barrier for C 2 products formation and accelerating the generation of ethylene and ethanol. This study pioneeringly establishes a novel pathway for selectively obtaining high-value energy products by controlling the component length. Download: Download high-res image (179KB) Download: Download full-size image The Cu 2 O/MOF composites with tunable MOF lengths were fabricated via a seed self-sacrifice strategy. By modulating the length of the outer MOF, the CO 2 concentration could be regulated, which promoted the formation and concentration of *CO. This process increased the coverage of the *CO adsorption layer on the Cu 2 O/MOF and lowered the energy barrier for the formation of the *CO*CO intermediate, thereby enabling the efficient generation of C 2 products.