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This especially relates to the behaviors of different classes of catalysts under operating conditions. Here, we analyzed the effects of local coordination of metal centers (Mn, Fe, Co) in graphene-embedded single-atom catalysts (SACs). We started with well-known M@N4-graphene catalysts and systematically replaced nitrogen atoms with oxygen or sulfur atoms to obtain M@OxNy-graphene and M@SxNy-graphene SACs (x + y = 4). We show that local coordination strongly affects the electronic structure and reactivity towards hydrogen and oxygen species. However, stability is even more affected. Using the concept of Pourbaix plots, we show that the replacement of nitrogen atoms in metal coordinating centers with O or S destabilized the SACs towards dissolution, while the metal centers were easily covered by O and OH, acting as additional ligands at high anodic potentials and high pH values. Thus, not only should local coordination be considered in terms of the activity of SACs, but it is also necessary to consider its effects on the speciation of SAC active centers under different potentials and pH conditions.<\/jats:p>","DOI":"10.3390\/nano12234309","type":"journal-article","created":{"date-parts":[[2022,12,5]],"date-time":"2022-12-05T04:40:09Z","timestamp":1670215209000},"page":"4309","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["The Local Coordination Effects on the Reactivity and Speciation of Active Sites in Graphene-Embedded Single-Atom Catalysts over Wide pH and Potential Range"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6115-1318","authenticated-orcid":false,"given":"Milica S.","family":"Ritope\u010dki","sequence":"first","affiliation":[{"name":"University of Belgrade\u2014Faculty of Physical Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6200-8612","authenticated-orcid":false,"given":"Ana S.","family":"Dobrota","sequence":"additional","affiliation":[{"name":"University of Belgrade\u2014Faculty of Physical Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natalia V.","family":"Skorodumova","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, School of Industrial Engineering and Management, KTH\u2014Royal Institute of Technology, Brinellv\u00e4gen 23, 100 44 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1000-9784","authenticated-orcid":false,"given":"Igor A.","family":"Pa\u0161ti","sequence":"additional","affiliation":[{"name":"University of Belgrade\u2014Faculty of Physical Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1007\/s40820-021-00668-6","article-title":"Engineering the Coordination Sphere of Isolated Active Sites to Explore the Intrinsic Activity in Single-Atom Catalysts","volume":"13","author":"Wu","year":"2021","journal-title":"Nano-Micro Lett."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"102938","DOI":"10.1016\/j.isci.2021.102938","article-title":"As a single atom Pd outperforms Pt as the most active co-catalyst for photocatalytic H2 evolution","volume":"24","author":"Cha","year":"2021","journal-title":"iScience"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1288","DOI":"10.1021\/acscentsci.0c00512","article-title":"Emerging Multifunctional Single-Atom Catalysts\/Nanozymes","volume":"6","author":"Zhang","year":"2020","journal-title":"ACS Cent. 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