Computational study of the conversion of methane and carbon dioxide to acetic acid over NU-1000 metal–organic framework-supported single-atom metal catalysts

Exploring the Opportunity of Missing Linker Defect-Induced Acetic Acid Synthesis over Heterometallic Fe2M-Based Metal–Organic Frameworks

“…20 Another study on acetic acid synthesis over Cu-atom-supported NU-1000 MOF showed the C−H bond dissociation to be rate limiting with an activation barrier of 28.4 kcal/mol. 31 Comparison with previous studies, therefore, points out that the activation barrier for the rate-limiting step (21.45 kcal/mol) for Fe 2 Cu is lower than the previously reported values, and hence, it can act as an effective catalyst for acetic acid synthesis from CO 2 and CH 4 . Moreover, since desorption of acetic acid is one of the major concerns for regeneration of catalyst, a value as low as 1.62 kcal/mol seems attractive�the desorption process is enhanced by a factor of about 12 when compared to the value reported by Montejo-Valencia et al for acetic acid desorption with coadsorption of water molecules.…”

“…A DFT study on acetic acid synthesis over Cu-modulated zeolites by Wang et al has pointed out MOR zeolite containing trinuclear copper-oxo cluster as the best-performing catalyst with the C–C coupling process as the rate-determining step (activation barrier of 35.61 kcal/mol) . Another study on acetic acid synthesis over Cu-atom-supported NU-1000 MOF showed the C–H bond dissociation to be rate limiting with an activation barrier of 28.4 kcal/mol . Comparison with previous studies, therefore, points out that the activation barrier for the rate-limiting step (21.45 kcal/mol) for Fe 2 Cu is lower than the previously reported values, and hence, it can act as an effective catalyst for acetic acid synthesis from CO 2 and CH 4 .…”

“…However, only a few reports on MOF-based catalysts for acetic acid synthesis from CH 4 and CO 2 exist. 28,31 Again, the existence of structural defects in MOFs has been proven to be beneficial for many catalytic applications. Missing linker defects in zirconiumoxide-based MOFs have been extensively studied.…”

“…39,44−46 Although a Fe 2 Cu-based MOF node has not been synthesized, we have considered it in our study because previous studies on acetic acid synthesis have shown that the copper sites in the catalytic system have the ability to effectively activate the C−H bond in CH 4 and in turn stabilize the methyl species. 20,26,27,29,31 The postsynthetic cation−exchange reaction has been used extensively to synthesize mixed-metal MOFs. 47,48 Szilaǵyi and co-workers have reported a procedure for Fe to Cr exchange in MIL-101(Cr), a MOF having a trimetallic node structure similar to MIL-127, producing a node of FeCr 2 composition.…”

Combined Experimental and Theoretical Study of the Synthesis of 5,7-Dihydroxy-4-methylcoumarin via a Pechmann Condensation in the Presence of UiO-66-SO3H Catalysts

“…The investigation of adsorption and reaction mechanisms within these catalysts was conducted by using density functional theory (DFT). DFT with M06 functional, in which the confinement effect was taken into account, has proven effective in studying the adsorption and reactions within UiO-66 catalysts and other heterogeneous catalysts. − This DFT functional was also applied to examine the reaction of 7-hydroxy-4-methylcoumarin synthesis using Beta zeolite . Structures and reactions within heterogeneous catalysts were studied with the ONIOM approach. , This method involved treating the active site and its related complexes with a high-accuracy level of calculation while employing a lower-accuracy calculation to depict the extended framework and represent the confinement effects of the environment.…”