A DFT Screening of M-HKUST-1 MOFs for Nitrogen-Containing Compounds Adsorption

Abstract

To develop promising adsorbent candidates for adsorptive denitrogenation, we screened the adsorption of NO, NO2, and NH3 in 19 M-HKUST-1 (M = Be, Fe, Ni, Cr, Co, Cu, V, Zn, Mo, Mn, W, Sn, Ti, Cd, Mg, Sc, Ca, Sr, and Ba) systematically using first-principle calculations. Of these, four variants of M-HKUST-1 (M = Ni, Co, V, and Sc) yield more negative adsorption Gibbs free energy ΔGads than the original Cu-HKUST-1 for three adsorbates, suggesting stronger adsorbate binding. Ti-HKUST-1, Sc-HKUST-1, and Be-HKUST-1 are predicted to have the largest NO, NO2, and NH3 adsorption energies within the screened M-HKUST-1 series, respectively. With the one exception of NO2 dissociation on V-HKUST-1, dissociative adsorption of NO, NO2, and NH3 molecules on the other considered M-HKUST-1 is energetically less favorable than molecular adsorption thermodynamically. The barrier calculations show that the dissociation is difficult to occur on Cu-HKUST-1 kinetically due to the very large dissociation barrier. Electronic analysis is provided to explain the bond nature between the adsorbates and M-HKUST-1. Note that the isostructural substitution of Cu to the other metals is a major simplification of the system, representing the ideal situation; however, the present study provides interesting targets for experimental synthesis and testing.

Mechanistic and Experimental Study of the Formation of MoS2/HKUST-1 Core–Shell Composites on MoS2 Quantum Dots with an Enhanced CO2 Adsorption Capacity

“…The interactions between CO 2 and HKUST-1 alone, together with the interactions between CO 2 and the MoS 2 /HKUST-1 core–shell composite, were modeled using the primitive cell of an MoS 2 nanosheet (4 × 4). Because of the massive structure of a complete HKUST-1, the SBU cluster is considered, which has been adopted by other researchers . Such a cluster contains one Cu–Cu paddlewheel unit connected by four organic linkers (carboxylate) to mimic the active sites of the HKUST-1 (Cu 3 (BTC) 2 ).…”

Modelling of porous metal-organic framework (MOF) materials used in catalysis

“…The two structures which showed the best properties were Mo-Cu-BTC and W-Cu-BTC, which can additionally be used as CO 2 hydrogenation catalysts. Interesting studies have also been conducted in the context of toxic gas capture by structure HKUST-1 (Zong et al, 2018). The adsorption of NO, NO 2 and NH 3 was analysed, and the structure was modified by exchanging copper atoms in Cu-BTC for other metal atoms.…”

The Adsorption of Small Molecules on the Copper Paddle-Wheel: Influence of the Multi-Reference Ground State

“…Consequently, prediction of adsorption energies of small molecules on this secondary building unit is of great practical interest [ 53 ]. Indeed, there are already a few studies in this direction [ 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ] performed mainly on the DFT level of theory, and in a few cases are combined with different ab initio approaches [ 63 , 64 , 65 ]. However, working with metal-organic compounds, one should always be aware of possible effects of multi-reference and, associated with that, issues on applicability of different methods.…”