Theoretical Investigation on the Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction Reactions Performances of Two-Dimensional Metal-Organic Frameworks Fe3(C2X)12 (X = NH, O, S)

Xiaohang Yang,Zhen Feng,Zhanyong Guo

doi:10.3390/molecules27051528

Abstract

Two-dimensional metal-organic frameworks (2D MOFs) inherently consisting of metal entities and ligands are promising single-atom catalysts (SACs) for electrocatalytic chemical reactions. Three 2D Fe-MOFs with NH, O, and S ligands were designed using density functional theory calculations, and their feasibility as SACs for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) was investigated. The NH, O, and S ligands can be used to control electronic structures and catalysis performance in 2D Fe-MOF monolayers by tuning charge redistribution. The results confirm the Sabatier principle, which states that an ideal catalyst should provide reasonable adsorption energies for all reaction species. The 2D Fe-MOF nanomaterials may render highly-efficient HER, OER, and ORR by tuning the ligands. Therefore, we believe that this study will serve as a guide for developing of 2D MOF-based SACs for water splitting, fuel cells, and metal-air batteries.

Highlights

The greenhouse effect, air pollution, ozone depletion, and fossil fuel depletion are all major challenges for our society’s progress in the 21st century [1]
A promising energy conversion technology is the unitized regenerative fuel cell. It works like a fuel cell and inversely as a water electrolyzer to produce H2 and O2 to feed the fuel cell
The first-principles calculations were performed with the context of spin-polarized DFT as implemented in the Vienna ab initio simulation package (VASP) [42]

Summary

Introduction

The greenhouse effect, air pollution, ozone depletion, and fossil fuel depletion are all major challenges for our society’s progress in the 21st century [1]. A promising energy conversion technology is the unitized regenerative fuel cell. It works like a fuel cell and inversely as a water electrolyzer to produce H2 and O2 to feed the fuel cell. TThhee uunniitt cceellllss ooff tthhee ssttuuddiieedd 22DD FFee--MMOOFF mmoonnoollaayyeerrss aarree ddeeppiicctteedd iinn FFiigguurree 11. TThheessee 22DD MMOOFF sshheeeettss aarree aallssoo aattoommiiccaallllyy tthhiinn lliikkee ggrraapphheemmee,, bbuutt eeaacchh uunniitt cceellll ccoonnssiissttss ooff 33 FFee aattoommss,, 2244 ccaarrbboonn aattoommss,, aanndd 1122 lliiggaattiinngg aattoommss. .NNoottaabbllyy, ,hhigighh--qquuaaliltityy22DDFFee--SSMMOOFF have been experimentallyy ssyynntthheessiizzeedd[[2277]],, hhoowweevveerr, their thermal stabilities were still performed using ffiirst-principles plus aabb iinniittiioo mmoolleeccuullaarr ddyynnaammiiccssssiimmuullaattiioonnss((AAIIMMDD))..AAttaatteemmppeerraattuurreeooff550000 KK,, aa ttoottaall ttiimmee pprroocceessss ooff 3000 fs with a time step ooff 11 ffsswwaassiimmpplleemmeenntteedduussiinnggssppeecciififeiedd22×× 1 ×× 11 rreeccttaanngguullaarr ssuuppeerrcceellllss (included 102 atoms for FFee--NNHH MMOOFF aanndd 7788 aattoommss ffoorr FFee--OO// FFee--SS MOFs). WWee ffuurrtthheerrppeerfroformrmBaBdaedrecrhcahragregaenaanlyasliysstios itnoveinstviegsattiegathtee cthheemchiceaml bicoanldbinogndinintgheisne tFhee-sMe OFeF-MmoOnFomlayoenrosl.aTyheerse. lTechteroenlelcotcroalnizlaotcioalnizfautniocntiofunn(EctLioFn) m(EaLpFa) nmdaipsoasnudrfiascoessuorffaEcLeFs owfiEthLaF vwailtuheaofv0a.l5u0eaouf a0r.5e0palouttaerdeipnlFoitgteudrein3aF–icg,utrhee3Fae–lco,stehse0F.5e8l–o1s.e5s1 0e,.5a8n–d1.t5h1eeN, a, nOd, athnde NS ,gOai,na0n.d13S–1g.a0i7ne0, .w13h–ic1h.07coen, twrihbiucthescotonttrhiebiurtreosbtuostthieoinricrobbounsdt si.oNnioctbeotnhdats.thNeopteostihtiavtethFee paotosmitivmeaFyebaetoumsemd aasyabne aucsteivdeassitaenfoarctcivheemsiitceaflorreachcteimonisc.al reactions

Electronic Property

Methods

Conclusions