@article {48193, title = {Doped 2D VX2 (X = S, Se, Te) monolayers as electrocatalysts for ammonia production: a DFT based study}, journal = {Applied Surface Science}, volume = {602}, year = {2022}, month = {NOV}, pages = {154401}, type = {Article}, abstract = {

Electrocatalytic nitrogen fixation under ambient conditions on vanadium dichalcogenides (VX2) with non-metal dopants has been explored herein. Understanding the interface chemistry, inherent electronic and acute synergistic nature of non-metal dopants on two unique phases of VX2 has been meticulously explored through a scrutiny of several non-metal atoms as catalytic centers. The efficacity of N-2 chemisorption and N-N bond activation has been implemented as crucial parameters to realize boron and carbon doped VX2 monolayers to be electrocatalytically active for nitrogen reduction reaction (NRR). Detailed investigation on the NRR mechanism brings out the pivotal role of thermodynamic favourability for product formation obtained from Gibbs free energy differences. The charge transfer on N and pi-pi* orbital hybridization and electron {\textquoteleft}{\textquoteleft}donor-acceptor {\textquoteleft}{\textquoteleft} mechanism between the non-metal and N-2 has been found to modulate the electrocatalytic barrier for NRR on VX2 monolayers. This study proposes boron doped VS2 as an efficient chemically feasible, earth abundant sustainable electrocatalyst for NRR with an overpotential as low as 0.06 eV.

}, keywords = {1T and 2H phases, DFT, electrocatalysts, Nitrogen Reduction Reaction, Non metal dopants, Vanadium dichalcogenides}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2022.154401}, author = {Maibam, Ashakiran and BabaRao, Ravichandar and Krishnamurty, Sailaj A.} } @article {48490, title = {Can Li atoms anchored on boron- and nitrogen-doped graphene catalyze dinitrogen molecules to ammonia? a DFT study}, journal = {ChemPhysChem}, volume = {24}, year = {2023}, month = {JUN}, type = {Article}, abstract = {

The most successful electrochemical conversion of ammonia from dinitrogen molecule reported to date is through a Li mediated mechanism. In the framework of the above fact and that Li anchored graphene is an experimentally feasible system, the present work is a computational experiment to identify the potential of Li anchored graphene as a catalyst for N-2 to NH3 conversion as a function of (a) minimum number of Li atoms needed for anchoring on graphene sheets and (b) the role of chemical modification of graphene surfaces. The studies bring forth an understanding that Li anchored graphene sheets are potential catalysts for ammonia conversion with preferential adsorption of N-2 through end-on configuration on Li atoms anchored on doped and pristine graphene surfaces. This mode of adsorption being characteristic of Nitrogen Reduction Reaction (NRR) through enzymatic pathway, examination of the same followed by analysis of electronic properties demonstrates that tri-Li atoms (Tri Atom Catalysts, TACs) are more efficient as catalysts for NRR as compared to two Li atoms (Di Atom Catalysts, DACs). Either way, the rate determining step was found to be *NH2 -\>*NH3 step (mixed pathway) with Delta G(max)=1.02 eV and *NH2-*NH3 -\>*NH2 step (enzymatic pathway) with Delta G(max)=1.11 eV for 1B doped TAC and DAC on graphene sheet, respectively. Consequently, this work identifies the viability of Li anchored graphene based 2-D sheets as hetero-atom catalyst for NRR.

}, keywords = {computational chemistry, Graphene Sheet, heterogeneous catalysis, Li Nanoparticles, Nitrogen Reduction Reaction}, issn = {1439-4235}, doi = {10.1002/cphc.202200750}, author = {Verma, Tushar Singh and Samal, Pragnya Paramita and Selvaraj, Kaliaperumal and Krishnamurty, Sailaja} } @article {49617, title = {Graphitic carbon nitride supported boron quantum dots: a transition metal free alternative for di-nitrogen to ammonia reaction}, journal = {CHEMPHYSCHEM}, volume = {26}, year = {2025}, month = {MAR}, type = {Article}, abstract = {

Presently, a sustainable electrochemical Nitrogen Reduction Reaction (NRR) has been essentially found to be viable on transition metal-based catalysts. However, being cost-effective and non-corrosive, metal-free catalysts present an ideal solution for a sustainable world. Herein, through a DFT-based study, we demonstrate metal-free NRR catalysts, boron quantum dots with 13 atoms as a case study and their chemically modified counterparts when anchored on graphitic carbon nitride (g-C3N4) surface. The best catalyst among the studied, a silicon-doped boron quantum dot with a cagelike structure, is found to favour the dinitrogen to ammonia reaction pathway with a low liming potential and potential rate-determining step (PDS) of -0.11 V and 0.27 eV, respectively. The present work demonstrates as to how boron quantum dots, which are reported to be experimentally synthesised, can be exploited for ammonia synthesis when supported on the surface. These catalysts effectively suppress the HER, thus establishing its suitability as an ideal catalyst. The work also represents a futuristic pathway towards a metal-free catalyst for NRR.

}, keywords = {Boron quantum dot, Electro-catalyst, Graphitic carbon nitride, hydrogen evolution reaction, Limiting potential, metal free catalyst, Nitrogen Reduction Reaction}, issn = {1439-4235}, doi = {10.1002/cphc.202400766}, author = {Samudre, Nikhil S. and Krishnamurty, Sailaja} }