Group IIIA Single-Metal Atoms Anchored on Hexagonal Boron Nitride for Selective Adsorption Desulfurization via S–M Bonds

Abstract

Single-atom adsorbents (SAAs) featuring maximized atom utilization and uniform isolated adsorption sites have aroused extensive research interest in recent years as a novel class of adsorption materials research. Nevertheless, it is still challenging to gain a fundamental understanding of the complicated behaviors of SAAs for adsorbing thiophenic compounds (THs). Herein, this work systematically investigated the mechanisms of adsorption desulfurization (ADS) over a single group IIIA metal atom (Ga, In, and Tl) anchored on hexagonal boron nitride nanosheets (BNNSs) via density functional theory (DFT) calculations. First, all the possible doping sites have been considered and their stabilities have been evaluated by the doped energy. DFT calculations reveal that metal atoms prefer to substitute B atoms on BNNSs rather than N atoms. Additionally, SAAs all exhibit considerably enhanced adsorption capacity for THs primarily by the sulfur-metal (S–M) bond with π–π interactions maintained. Among them, In-atom-based SAAs would be adequate to provide the highest adsorption energy (In_cen_B, −40.1 kcal mol–1). Furthermore, from the perspective of adsorption energy, the SAAs show superior selectivity to THs than aromatic compounds due to the newly formed S–M bond. We hope that our work will manifest the design and application of SAAs in the field of ADS and shed light on a new strategy for fabricating SAAs based on BNNSs.

Crystal-Plane-Engineered TiO2-Anchored Vanadium Single Atoms and Clusters for Boosting Ultradeep Aerobic Oxidative Desulfurization of Diesel

“…The calculated adsorption energy of 4,6-DMDBT on the VO x /TiO 2 -(101), VO x /TiO 2 -(100), and VO x /TiO 2 -(001) surfaces is 0.67, 0.10, and 0.30 eV, respectively. It has been well-established that too strong or too weak adsorption energies of aromatic sulphides with catalytic active sites on catalyst surfaces are both unfavorable for the AODS process. , Therein, too strong an adsorption energy of aromatic sulfides with catalytic active sites would “poison” the catalyst, while too weak an adsorption energy is unfavorable for the full contact of the reactant with catalytic active sites. Thus, the suitable adsorption energy of 4,6-DMDBT on VO x /TiO 2 -(101) indicates the better activation effect on VO x /TiO 2 -(101) catalysts, which is in accordance with the experimental and AODS results.…”

Atomically Dispersed Aluminum Sites in Hexagonal Boron Nitride Nanofibers for Boosting Adsorptive Desulfurization Performance

“…21−23 However, the aromatic compounds in fuel compete with TS for adsorption on the surface of BNNFs, which pose a huge impact on the selectivity for TS. 21 For ADS application of BNNFs, doping the metal elements onto BNbased materials was reported to be more effective and selective toward eliminating the TS from fuel compared to pristine BN materials. 21,24,25 Recently, our previous theoretical study 21 demonstrated that single-metal atom adsorbents (SAAs), with atomically dispersed group IIIA metal sites, based on boron nitride nanosheets have remarkable adsorption performance for TS through S−M interactions between the sulfur atom in TS and the metal atom in the adsorbent.…”

“…21 For ADS application of BNNFs, doping the metal elements onto BNbased materials was reported to be more effective and selective toward eliminating the TS from fuel compared to pristine BN materials. 21,24,25 Recently, our previous theoretical study 21 demonstrated that single-metal atom adsorbents (SAAs), with atomically dispersed group IIIA metal sites, based on boron nitride nanosheets have remarkable adsorption performance for TS through S−M interactions between the sulfur atom in TS and the metal atom in the adsorbent. SAAs are an emerging strategy of adsorbents with atomically dispersed adsorption sites anchored on support materials.…”

“…Recently, our previous theoretical study demonstrated that single-metal atom adsorbents (SAAs), with atomically dispersed group IIIA metal sites, based on boron nitride nanosheets have remarkable adsorption performance for TS through S–M interactions between the sulfur atom in TS and the metal atom in the adsorbent. SAAs are an emerging strategy of adsorbents with atomically dispersed adsorption sites anchored on support materials. , Moreover, shrinking the size of bulk or nanometal materials to isolated atoms, doped in a supporting matrix, achieves the maximum utilization efficiency of the metal. , Due to this encouraging feature, SAAs exhibit unconventional adsorption performance in comparison with bulk or nanometal-based adsorbents, which sparked the development of general synthetic strategies of single-atom materials.…”

“…Previous studies ,− have reported a two-dimensional planar structure of the BNNF composed alternately of boron (B) and nitrogen (N) atoms. Accordingly, the π–π interactions, formed by the BNNF with the TS, can be devoted to removing the TS from fuel in the ADS process. − However, the aromatic compounds in fuel compete with TS for adsorption on the surface of BNNFs, which pose a huge impact on the selectivity for TS . For ADS application of BNNFs, doping the metal elements onto BN-based materials was reported to be more effective and selective toward eliminating the TS from fuel compared to pristine BN materials. ,, …”