Pub Date : 2025-12-12DOI: 10.1016/j.susc.2025.122910
Guozheng Zhao, Zhongfei Xia, Jianfeng Jia
The adsorption and activation of nitrobenzene on transition-metal clusters were systematically investigated using density functional theory (DFT) calculations. A truncated octahedral model exposing both (111) and (100) facets was employed to represent Cu, Ag, and Au clusters, and multiple adsorption configurations were fully optimized. Geometrical analyses demonstrate that nitrobenzene preferentially adsorbs at boundary sites where (111) and (100) facets meet, with Cu providing the strongest binding accompanied by pronounced N–O bond elongation and C–N contraction. Mulliken charge population and projected density of states (PDOS) reveal significant metal-to-adsorbate electron transfer, particularly to the oxygen atoms, thereby weakening the N–O bonds and facilitating nitro group activation. Frontier orbital analysis shows strong overlap between oxygen 2p and metal d states in the HOMO region, along with LUMO delocalization over the nitro group and the cluster, confirming efficient orbital hybridization. These findings establish that Cu clusters provide asymmetric activation favoring stepwise N–O bond cleavage, Ag induces more symmetric dual N–O weakening, and Au leads to weaker yet asymmetric activation. This work provides a comprehensive mechanistic understanding of nitrobenzene activation on coinage-metal clusters and offers theoretical insights into the rational design of catalytic systems for selective nitro reduction.
{"title":"First-principles investigation of nitrobenzene adsorption and activation on Cu, Ag, and Au clusters: Geometrical, energetic, and electronic insights","authors":"Guozheng Zhao, Zhongfei Xia, Jianfeng Jia","doi":"10.1016/j.susc.2025.122910","DOIUrl":"10.1016/j.susc.2025.122910","url":null,"abstract":"<div><div>The adsorption and activation of nitrobenzene on transition-metal clusters were systematically investigated using density functional theory (DFT) calculations. A truncated octahedral model exposing both (111) and (100) facets was employed to represent Cu, Ag, and Au clusters, and multiple adsorption configurations were fully optimized. Geometrical analyses demonstrate that nitrobenzene preferentially adsorbs at boundary sites where (111) and (100) facets meet, with Cu providing the strongest binding accompanied by pronounced N–O bond elongation and C–N contraction. Mulliken charge population and projected density of states (PDOS) reveal significant metal-to-adsorbate electron transfer, particularly to the oxygen atoms, thereby weakening the N–O bonds and facilitating nitro group activation. Frontier orbital analysis shows strong overlap between oxygen 2<em>p</em> and metal <em>d</em> states in the HOMO region, along with LUMO delocalization over the nitro group and the cluster, confirming efficient orbital hybridization. These findings establish that Cu clusters provide asymmetric activation favoring stepwise N–O bond cleavage, Ag induces more symmetric dual N–O weakening, and Au leads to weaker yet asymmetric activation. This work provides a comprehensive mechanistic understanding of nitrobenzene activation on coinage-metal clusters and offers theoretical insights into the rational design of catalytic systems for selective nitro reduction.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122910"},"PeriodicalIF":1.8,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.susc.2025.122909
Zhihong Zheng, Lifeng Wang, Xiaopeng Yang, Yizhong Lu
As a brand-new two-dimensional semiconductor material, C3N has excellent electrical and magnetic properties. It is an emerging material for making gas sensors. In this paper, based on first principles and Density Functional Theory (DFT), we investigate the properties exhibited by C3N when different gases adsorbed on it. These gases include harmful ones that have not been studied before, and the calculation of electrical conductivity is introduced to evaluate the effect of gas adsorption on the electrical conductivity of C3N. Because of the weak interaction between C3N and CH3OH, HCHO, COCl2, CH4, H2S, N2, NH3, no charge overlap is generated and the gas molecules are considered to be physisorbed. There are weak chemical bonds between HCl, HBr, HCN and C3N, which exhibit weak chemisorption. The strong interaction between C2H2, Cl2 and C3N forms a chemical bond, which is manifested as chemisorption, and changes the electronic properties of C3N after adsorption. This suggests that C3N has great potential for the detection of C2H2 and Cl2.
{"title":"Theoretical study of gas adsorption properties of a two-dimensional C3N layer","authors":"Zhihong Zheng, Lifeng Wang, Xiaopeng Yang, Yizhong Lu","doi":"10.1016/j.susc.2025.122909","DOIUrl":"10.1016/j.susc.2025.122909","url":null,"abstract":"<div><div>As a brand-new two-dimensional semiconductor material, C<sub>3</sub>N has excellent electrical and magnetic properties. It is an emerging material for making gas sensors. In this paper, based on first principles and Density Functional Theory (DFT), we investigate the properties exhibited by C<sub>3</sub>N when different gases adsorbed on it. These gases include harmful ones that have not been studied before, and the calculation of electrical conductivity is introduced to evaluate the effect of gas adsorption on the electrical conductivity of C<sub>3</sub>N. Because of the weak interaction between C<sub>3</sub>N and CH<sub>3</sub>OH, HCHO, COCl<sub>2</sub>, CH<sub>4</sub>, H<sub>2</sub>S, N<sub>2</sub>, NH<sub>3</sub>, no charge overlap is generated and the gas molecules are considered to be physisorbed. There are weak chemical bonds between HCl, HBr, HCN and C<sub>3</sub>N, which exhibit weak chemisorption. The strong interaction between C<sub>2</sub>H<sub>2</sub>, Cl<sub>2</sub> and C<sub>3</sub>N forms a chemical bond, which is manifested as chemisorption, and changes the electronic properties of C<sub>3</sub>N after adsorption. This suggests that C<sub>3</sub>N has great potential for the detection of C<sub>2</sub>H<sub>2</sub> and Cl<sub>2</sub>.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122909"},"PeriodicalIF":1.8,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The reversibility of hydrogen absorption and desorption dictates the cycling stability of hydrides. This stability is a critical benchmark for their viability as hydrogen storage media. This study employs First-principles study to unravel the stability, hydrogen desorption, and diffusion mechanisms at the TiH₂(111)/Mg7TiH16(111) interface. Our findings demonstrate that interface formation induces significant atomic rearrangement and charge redistribution, thereby affecting its stability. The dehydrogenation behavior is critically dependent on the specific atomic configuration at the interface, with hydrogen release preferentially occurring within the Mg7TiH16 side due to its lower dehydrogenation energy. Analysis of diffusion barriers and bond cleavage energies suggests a dehydrogenation mechanism initiated at the interface, where the weakening of metal-hydrogen bonds in Mg7TiH16 acts as the primary driver. These results provide a theoretical foundation for understanding the interfacial hydrogen desorption process and advocate multilayer interface engineering as a promising strategy to boost the reversible hydrogen storage performance of Mg-based hydrides.
{"title":"Enhancing the reversibility of Mg7TiH16 via interfacial engineering with TiH2: First principles study","authors":"Yuying Chen , Jianfeng Wang , Yuting Chen , Jiaxuan Tang , Ruiyang Qu","doi":"10.1016/j.susc.2025.122908","DOIUrl":"10.1016/j.susc.2025.122908","url":null,"abstract":"<div><div>The reversibility of hydrogen absorption and desorption dictates the cycling stability of hydrides. This stability is a critical benchmark for their viability as hydrogen storage media. This study employs First-principles study to unravel the stability, hydrogen desorption, and diffusion mechanisms at the TiH₂(111)/Mg<sub>7</sub>TiH<sub>16</sub>(111) interface. Our findings demonstrate that interface formation induces significant atomic rearrangement and charge redistribution, thereby affecting its stability. The dehydrogenation behavior is critically dependent on the specific atomic configuration at the interface, with hydrogen release preferentially occurring within the Mg<sub>7</sub>TiH<sub>16</sub> side due to its lower dehydrogenation energy. Analysis of diffusion barriers and bond cleavage energies suggests a dehydrogenation mechanism initiated at the interface, where the weakening of metal-hydrogen bonds in Mg<sub>7</sub>TiH<sub>16</sub> acts as the primary driver. These results provide a theoretical foundation for understanding the interfacial hydrogen desorption process and advocate multilayer interface engineering as a promising strategy to boost the reversible hydrogen storage performance of Mg-based hydrides.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122908"},"PeriodicalIF":1.8,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.susc.2025.122897
Rafael Reis Barreto , Iago Aédon Silva Prior , Eidsa Brenda da Costa Ferreira , Vanessa Carreño-Diaz , Igor Stein Weiler , Alisson Steffli Thill , Fabiano Bernardi , Abner de Siervo
In this study, we report a surface-confined metal–organic networks (SMON) obtained by post-depositing Fe onto a sub-monolayer of 5,10,15,20-tetra(4-pyridyl)porphyrin on Ag(100) and activating at 350 K. Scanning tunneling microscopy (STM) reveals a rectangular/square lattice built from pyridyl–Fe–pyridyl nodes, coexisting with close-packed TPyP domains. Two reproducible junction motifs emerge at identical lattice positions: high-contrast nodes and lower-contrast nodes, consistent with, respectively, an on-top Fe bridge above and below the pyridyl plane, which is stabilized closer to Ag(100). Raising the activation temperature by heat treatment to 400 K, the island density decreases, and the median island size increases. Increasing the Fe dose at 350 K, the islands grow up to 90 molecules per island before a plateau, indicating a crossover from diffusion-limited to site/supply-limited growth. At 450 K, intramolecular metalation proceeds without long-range coordination, resulting in a metalated, but unlinked, monolayer. These observations establish a temperature and dose window for assembling Fe–TPyP SMON on Ag(100) and highlight how substrate registry and coordination chemistry produce distinct junction heights within an otherwise rigid square metric. We report a new motif that appears at 350 K, characterized by an ordered phase resembling a double-lobed linker node that forms extended domains.
{"title":"Square Fe–TPyP metal–organic framework on Ag(100) showing high/low junction variants and dose-dependent growth","authors":"Rafael Reis Barreto , Iago Aédon Silva Prior , Eidsa Brenda da Costa Ferreira , Vanessa Carreño-Diaz , Igor Stein Weiler , Alisson Steffli Thill , Fabiano Bernardi , Abner de Siervo","doi":"10.1016/j.susc.2025.122897","DOIUrl":"10.1016/j.susc.2025.122897","url":null,"abstract":"<div><div>In this study, we report a surface-confined metal–organic networks (SMON) obtained by post-depositing Fe onto a sub-monolayer of 5,10,15,20-tetra(4-pyridyl)porphyrin on Ag(100) and activating at 350 K. Scanning tunneling microscopy (STM) reveals a rectangular/square lattice built from pyridyl–Fe–pyridyl nodes, coexisting with close-packed TPyP domains. Two reproducible junction motifs emerge at identical lattice positions: high-contrast nodes and lower-contrast nodes, consistent with, respectively, an on-top Fe bridge above and below the pyridyl plane, which is stabilized closer to Ag(100). Raising the activation temperature by heat treatment to 400 K, the island density decreases, and the median island size increases. Increasing the Fe dose at 350 K, the islands grow up to <span><math><mo>∼</mo></math></span>90 molecules per island before a plateau, indicating a crossover from diffusion-limited to site/supply-limited growth. At 450 K, intramolecular metalation proceeds without long-range coordination, resulting in a metalated, but unlinked, monolayer. These observations establish a temperature and dose window for assembling Fe–TPyP SMON on Ag(100) and highlight how substrate registry and coordination chemistry produce distinct junction heights within an otherwise rigid square metric. We report a new motif that appears at 350 K, characterized by an ordered phase resembling a double-lobed linker node that forms extended domains.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122897"},"PeriodicalIF":1.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.susc.2025.122906
Jianxin Wang, Jinzhe Zhang, Qun Cai
The metal-catalyzed gas etching of graphene can efficiently obtain one-dimensional boundaries or nanoribbons in situ for further physical property measurement and exploration. Therefore, the studies to the structural details and their evolutions during etching are of great interest. In this work, silver is used as a catalyst for assisting oxygen to etch nanochannels on the surface of epitaxial graphene/SiC. A series of comparative experiments have been performed by using scanning tunneling microscopy, Raman spectroscopy and other research methods to investigate the effects of oxygen exposure and silver coverage. It is shown that O2 and Ag play a synergistic role in the etching process. The optimum oxygen pressure for the etching is in the range of 10–3 Torr, and the silver coverage needs to be >0.5ML. The experimental results reveal that annealing with oxygen exposure can also corrode the SiC layer, forming the fragmented nanostructures with sizes <10 nm at the early stage of etching. Two types of etching channels are observed on the sample surface with 1.5ML Ag. This work can pave the way for obtaining the well-controlled graphene boundaries or nanostructures with atom decoration on SiC substrates.
{"title":"Exploration of Ag-assisted oxygen etching on epitaxial graphene","authors":"Jianxin Wang, Jinzhe Zhang, Qun Cai","doi":"10.1016/j.susc.2025.122906","DOIUrl":"10.1016/j.susc.2025.122906","url":null,"abstract":"<div><div>The metal-catalyzed gas etching of graphene can efficiently obtain one-dimensional boundaries or nanoribbons <em>in situ</em> for further physical property measurement and exploration. Therefore, the studies to the structural details and their evolutions during etching are of great interest. In this work, silver is used as a catalyst for assisting oxygen to etch nanochannels on the surface of epitaxial graphene/SiC. A series of comparative experiments have been performed by using scanning tunneling microscopy, Raman spectroscopy and other research methods to investigate the effects of oxygen exposure and silver coverage. It is shown that O<sub>2</sub> and Ag play a synergistic role in the etching process. The optimum oxygen pressure for the etching is in the range of 10<sup>–3</sup> Torr, and the silver coverage needs to be >0.5<em>ML</em>. The experimental results reveal that annealing with oxygen exposure can also corrode the SiC layer, forming the fragmented nanostructures with sizes <10 <em>nm</em> at the early stage of etching. Two types of etching channels are observed on the sample surface with 1.5<em>ML</em> Ag. This work can pave the way for obtaining the well-controlled graphene boundaries or nanostructures with atom decoration on SiC substrates.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122906"},"PeriodicalIF":1.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harnessing ethanol as an alternative to fossil fuels is crucial for ensuring sustainability in the global energy sector. The direct ethanol fuel cell (DEFC) has emerged as one of the leading technologies for converting ethanol into electricity. Ethanol oxidation reaction (EOR) is the key process that controls the performance of DEFC. Therefore, in this study, we investigated the EOR process over PdCu alloy surfaces. The catalytic activity was also compared to that of pristine Pd and Cu to showcase the superiority of PdCu alloy in catalyzing EOR. Since the EOR network comprises several possible reaction pathways, it is essential to analyze the preferred pathway over each catalyst surface. CC bond cleavage is essential to DEFC technology, as it produces more electrons, thereby increasing its efficiency. Our results demonstrated the ability of the PdCu alloy to reduce the activation energy of CC cleavage to 0.92 eV, which is significantly lower than that of pristine Pd and Cu catalysts. Moreover, it is noteworthy that a surface composed of Pd and Cu is desirable, rather than a simple coating of the Pd surface with Cu. The findings from this research are valuable in designing a suitable catalyst to maximize DEFC performance.
{"title":"First-principles investigation on ethanol oxidation reaction over PdCu alloy surfaces for direct ethanol fuel cell applications","authors":"Patrik Chandra , Mufidzatul Nur Hidayah , Karna Wijaya , Lala Adetia Marlina , Aulia Sukma Hutama","doi":"10.1016/j.susc.2025.122907","DOIUrl":"10.1016/j.susc.2025.122907","url":null,"abstract":"<div><div>Harnessing ethanol as an alternative to fossil fuels is crucial for ensuring sustainability in the global energy sector. The direct ethanol fuel cell (DEFC) has emerged as one of the leading technologies for converting ethanol into electricity. Ethanol oxidation reaction (EOR) is the key process that controls the performance of DEFC. Therefore, in this study, we investigated the EOR process over PdCu alloy surfaces. The catalytic activity was also compared to that of pristine Pd and Cu to showcase the superiority of PdCu alloy in catalyzing EOR. Since the EOR network comprises several possible reaction pathways, it is essential to analyze the preferred pathway over each catalyst surface. C<img>C bond cleavage is essential to DEFC technology, as it produces more electrons, thereby increasing its efficiency. Our results demonstrated the ability of the PdCu alloy to reduce the activation energy of C<img>C cleavage to 0.92 eV, which is significantly lower than that of pristine Pd and Cu catalysts. Moreover, it is noteworthy that a surface composed of Pd and Cu is desirable, rather than a simple coating of the Pd surface with Cu. The findings from this research are valuable in designing a suitable catalyst to maximize DEFC performance.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122907"},"PeriodicalIF":1.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.susc.2025.122905
Qing-Yun Wang, Xin-Yuan Xie, Yong-Chun Tong, Mei Wang, Gui-Rong Liu, Pei-Yue Li
Based on first-principles calculation methods, we conducted a systematic investigation into the adsorption and conversion processes of polysulfides on the surfaces of undoped, Mn-doped, P-doped, and MnP co-doped MoS₂. The research findings reveal that the MnP co-doped MoS₂ structure possesses a relatively low formation energy. This characteristic enables it to exhibit exceptional adsorptivity, thereby effectively achieving stable anchoring of lithium polysulfides (LiPSs). Meanwhile, for the MnP-MoS₂ system, we observed that the synergistic effect significantly enhances the binding energy of LiPSs on the MoS₂ surface. This dual-doping strategy not only effectively promotes the conversion of polysulfides into the final products but also constructs a low-energy-barrier pathway for the decomposition of Li₂S, thereby significantly accelerating the kinetic reaction rates during the charge-discharge processes of lithium-sulfur (Li-S) batteries. Particularly noteworthy is that MnP-MoS₂ leads to a substantial reduction in the Gibbs free energy change from S₈ to Li₂S. This change provides more favorable thermodynamic conditions for the smooth progress of battery reactions.
{"title":"Optimizing the performance of lithium-sulfur battery cathodes: A first-principles study on MnP Co-doped MoS2","authors":"Qing-Yun Wang, Xin-Yuan Xie, Yong-Chun Tong, Mei Wang, Gui-Rong Liu, Pei-Yue Li","doi":"10.1016/j.susc.2025.122905","DOIUrl":"10.1016/j.susc.2025.122905","url":null,"abstract":"<div><div>Based on first-principles calculation methods, we conducted a systematic investigation into the adsorption and conversion processes of polysulfides on the surfaces of undoped, Mn-doped, P-doped, and MnP co-doped MoS₂. The research findings reveal that the MnP co-doped MoS₂ structure possesses a relatively low formation energy. This characteristic enables it to exhibit exceptional adsorptivity, thereby effectively achieving stable anchoring of lithium polysulfides (LiPSs). Meanwhile, for the MnP-MoS₂ system, we observed that the synergistic effect significantly enhances the binding energy of LiPSs on the MoS₂ surface. This dual-doping strategy not only effectively promotes the conversion of polysulfides into the final products but also constructs a low-energy-barrier pathway for the decomposition of Li₂S, thereby significantly accelerating the kinetic reaction rates during the charge-discharge processes of lithium-sulfur (Li-S) batteries. Particularly noteworthy is that MnP-MoS₂ leads to a substantial reduction in the Gibbs free energy change from S₈ to Li₂S. This change provides more favorable thermodynamic conditions for the smooth progress of battery reactions.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122905"},"PeriodicalIF":1.8,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.susc.2025.122904
Philipp A. Fredersdorff , Jan Smyczek , Carsten Schröder , Paul Kohlmorgen , Paul Fröhlich , Patrick Hubert , Stephan Appenfeller , Konstantin M. Neyman , Swetlana Schauermann
Single atom alloys (SAAs) offer a powerful strategy to achieve high catalytic selectivity while minimizing the use of expensive noble metals. Control over their selectivity requires a fundamental-level understanding of how it depends on the electronic structure and geometric arrangement of the active single atoms embedded into the host matrix as well as how these properties are affected by the alloy composition and the preparation conditions. Here, we present a comprehensive study of Pd/Cu(111) surfaces over a wide range of Pd coverages (0.01–0.55 ML), combining infrared reflection absorption spectroscopy (IRAS) employing CO as a highly sensitive probe for different adsorption sites, scanning tunneling microscopy (STM), synchrotron-based high-resolution X-ray photoelectron spectroscopy (HR-XPS), temperature-programmed desorption (TPD), and density functional theory (DFT) calculations. Specifically, the correlation of the IRAS, STM and HR-XPS data, which were obtained as a function of changing preparation parameters (Pd loading and annealing temperature), allowed to identify three different forms of Pd: (i) single Pd atoms embedded into Cu, (ii) Pd ensembles consisting of several Pd atoms and residing on Cu surface as well as (iii) subsurface Pd formed as a result of Pd diffusion into Cu bulk. Immediately after deposition at 300 K, Pd nucleates preferentially at step edges of the Cu(111) crystal, forming isolated Pd atoms at coverages below 0.1 ML and larger Pd ensembles at higher Pd loadings. At coverages above 0.55 ML, 3D Pd clusters emerge near the step edges. Annealing to 550 K significantly alters this distribution: Pd diffuses to terrace sites, forming isolated atoms and leading to disintegration of Pd ensembles. Up to 0.3 ML, isolated Pd atoms dominate on terraces, while ensembles are absent. At coverages exceeding 0.3 ML, however, both IRAS and XPS reveal reformation of Pd ensembles.
The structural information was linked to the catalytic performance in butanol dehydrogenation to butanal and decomposition to CO. TPD experiments correlated with the structural information on the surface composition suggest that isolated Pd atoms embedded in the Cu(111) terrace selectively catalyze butanal formation, while Pd ensembles promote extensive C–C and C–H bond scission, yielding CO. However, when Pd atoms are located at the step edges, both pathways occur, indicating that the low-coordinated environment enables not only H abstraction but also C–C bond cleavage in butanol. DFT calculations reveal similar electronic structures for isolated Pd atoms embedded into the (111) terraces and step edges, suggesting that reactivity differences arise primarily from the geometric effects. With this, the local geometric environment of the active metal emerges as highly important factor governing selectivity in alcohol dehydrogenation.
{"title":"Surface composition of Pd/Cu(111) single-atom alloys and its impact on selective non-oxidative butanol dehydrogenation","authors":"Philipp A. Fredersdorff , Jan Smyczek , Carsten Schröder , Paul Kohlmorgen , Paul Fröhlich , Patrick Hubert , Stephan Appenfeller , Konstantin M. Neyman , Swetlana Schauermann","doi":"10.1016/j.susc.2025.122904","DOIUrl":"10.1016/j.susc.2025.122904","url":null,"abstract":"<div><div>Single atom alloys (SAAs) offer a powerful strategy to achieve high catalytic selectivity while minimizing the use of expensive noble metals. Control over their selectivity requires a fundamental-level understanding of how it depends on the electronic structure and geometric arrangement of the active single atoms embedded into the host matrix as well as how these properties are affected by the alloy composition and the preparation conditions. Here, we present a comprehensive study of Pd/Cu(111) surfaces over a wide range of Pd coverages (0.01–0.55 ML), combining infrared reflection absorption spectroscopy (IRAS) employing CO as a highly sensitive probe for different adsorption sites, scanning tunneling microscopy (STM), synchrotron-based high-resolution X-ray photoelectron spectroscopy (HR-XPS), temperature-programmed desorption (TPD), and density functional theory (DFT) calculations. Specifically, the correlation of the IRAS, STM and HR-XPS data, which were obtained as a function of changing preparation parameters (Pd loading and annealing temperature), allowed to identify three different forms of Pd: <em>(i)</em> single Pd atoms embedded into Cu, <em>(ii)</em> Pd ensembles consisting of several Pd atoms and residing on Cu surface as well as <em>(iii)</em> subsurface Pd formed as a result of Pd diffusion into Cu bulk. Immediately after deposition at 300 K, Pd nucleates preferentially at step edges of the Cu(111) crystal, forming isolated Pd atoms at coverages below 0.1 ML and larger Pd ensembles at higher Pd loadings. At coverages above 0.55 ML, 3D Pd clusters emerge near the step edges. Annealing to 550 K significantly alters this distribution: Pd diffuses to terrace sites, forming isolated atoms and leading to disintegration of Pd ensembles. Up to 0.3 ML, isolated Pd atoms dominate on terraces, while ensembles are absent. At coverages exceeding 0.3 ML, however, both IRAS and XPS reveal reformation of Pd ensembles.</div><div>The structural information was linked to the catalytic performance in butanol dehydrogenation to butanal and decomposition to CO. TPD experiments correlated with the structural information on the surface composition suggest that isolated Pd atoms embedded in the Cu(111) terrace selectively catalyze butanal formation, while Pd ensembles promote extensive C–C and C–H bond scission, yielding CO. However, when Pd atoms are located at the step edges, both pathways occur, indicating that the low-coordinated environment enables not only H abstraction but also C–C bond cleavage in butanol. DFT calculations reveal similar electronic structures for isolated Pd atoms embedded into the (111) terraces and step edges, suggesting that reactivity differences arise primarily from the geometric effects. With this, the local geometric environment of the active metal emerges as highly important factor governing selectivity in alcohol dehydrogenation.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122904"},"PeriodicalIF":1.8,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The WS2 thin layers were deposited on SiO2 /Si substrate by pulsed laser deposition (PLD). The third harmonic Q switched Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser of 355 nm wavelength and nanosecond pulse duration was used. The laser energy was tuned between 20 mJ to 30 mJ. The influence of the laser energy on the thickness, optical and electrical transport properties of the layers was studied. The A1g (Γ) & E12g(Γ) Raman peak position difference increased and the I E12g/I A1g peak intensity ratio decreased with the increase of the laser energy. It indicated the increase in the number of WS2 layers with the increase of the laser energy. The X-ray diffraction (XRD) showed a mixed polymorphic phase of 2H and 1T WS2. It also indicated prominent (002) 2H WS2 peak for 25 mJ and 30 mJ laser energy and an additional 1T WS2 peak for 20 mJ laser energy. The energy-dispersive X-ray (EDX) analysis showed S (Sulfur) deficient WS2 layers. The spectroscopic ellipsometry (SE) was used to determine layer thickness, bandgap, electrical conductivity and carrier mobility of the layers. The SE fitted results showed WS2 layer thickness of 0.7 nm, 1.4 nm & 2.0 nm for laser energy of 20 mJ, 25 mJ & 30 mJ, respectively. The SE fitted data showed that the conductivity and the bandgap decreased with the increase of the laser energy. The uniqueness of the study lies on low laser energy investigation of PLD and optical and electrical characterization of WS2 layers by SE.
{"title":"Facile synthesis of pulsed laser deposited polymorphic WS2 nanolayers and manipulation of layer thickness by tuning laser energy","authors":"Bidyut Bhattacharjee , Ashwini Kumar Sharma , Gobinda Pradhan","doi":"10.1016/j.susc.2025.122893","DOIUrl":"10.1016/j.susc.2025.122893","url":null,"abstract":"<div><div>The WS<sub>2</sub> thin layers were deposited on SiO<sub>2</sub> /Si substrate by pulsed laser deposition (PLD). The third harmonic Q switched Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser of 355 nm wavelength and nanosecond pulse duration was used. The laser energy was tuned between 20 mJ to 30 mJ. The influence of the laser energy on the thickness, optical and electrical transport properties of the layers was studied. The A<sub>1g</sub> (Γ) & E<sup>1</sup><sub>2g</sub>(Γ) Raman peak position difference increased and the I E<sup>1</sup><sub>2g</sub>/I A<sub>1g</sub> peak intensity ratio decreased with the increase of the laser energy. It indicated the increase in the number of WS<sub>2</sub> layers with the increase of the laser energy. The X-ray diffraction (XRD) showed a mixed polymorphic phase of 2H and 1T WS<sub>2</sub>. It also indicated prominent (002) 2H WS<sub>2</sub> peak for 25 mJ and 30 mJ laser energy and an additional 1T WS<sub>2</sub> peak for 20 mJ laser energy. The energy-dispersive X-ray (EDX) analysis showed S (Sulfur) deficient WS<sub>2</sub> layers. The spectroscopic ellipsometry (SE) was used to determine layer thickness, bandgap, electrical conductivity and carrier mobility of the layers. The SE fitted results showed WS<sub>2</sub> layer thickness of 0.7 nm, 1.4 nm & 2.0 nm for laser energy of 20 mJ, 25 mJ & 30 mJ, respectively. The SE fitted data showed that the conductivity and the bandgap decreased with the increase of the laser energy. The uniqueness of the study lies on low laser energy investigation of PLD and optical and electrical characterization of WS<sub>2</sub> layers by SE.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122893"},"PeriodicalIF":1.8,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.susc.2025.122894
Majid Poormohamadi, Hossein Roohi
Efficient detection and removal of sulfur dioxide (SO2) from the atmosphere are critical for environmental protection and public health. In this work, we employ quantum engineering approaches to explore the potential of metal-doped and vacancy-modified gallium sulfide monolayers (GaSMLs) as reusable and sensitive SO₂ gas sensors. Using Grimme DFT-D approach, we systematically investigate the adsorption energies, charge transfer characteristics, electronic structure changes, work function modifications, and recovery times for SO₂ adsorption on pristine, vacancy-defective, and various metal-doped GaSML configurations. The adsorption energies calculated for GaSMLs (pristine and defective) range from −9.27 to −49.0 kcal/mol for sulfur-site modifications and from −3.0 to −9.59 kcal/mol for gallium-site modifications, demonstrating a wide range of adsorption capabilities that can be systematically modulated through defect engineering. Our results reveal that metal doping at sulfur sites, particularly with Mn, Cr, and Ni, significantly enhances SO₂ adsorption strength, charge transfer, and work function, accompanied by a notable narrowing of the band gap. These doped systems exhibit a balanced recovery time ranging from hundreds to thousands of seconds, suggesting practical reusability with mild external stimuli. Vacancy defects at sulfur sites also offer promising sensor performance with rapid desorption kinetics. Conversely, Fe doping, despite exhibiting the strongest adsorption, results in prohibitively long recovery times, limiting sensor applicability. This integrated analysis identifies Mn, Cr, and Ni-doped GaSMLs as optimal candidates for high-performance, reusable SO₂ sensors, capable of efficient environmental SO₂ clearance. These findings provide valuable insights for the rational design of two-dimensional materials engineered at the quantum level for sustainable gas sensing and pollution control.
{"title":"Quantum-engineered metal-doped and vacancy-modified GaS Monolayers for efficient SO₂ gas sensing: insights from adsorption, electronic structure, and recovery dynamics","authors":"Majid Poormohamadi, Hossein Roohi","doi":"10.1016/j.susc.2025.122894","DOIUrl":"10.1016/j.susc.2025.122894","url":null,"abstract":"<div><div>Efficient detection and removal of sulfur dioxide (SO<sub>2</sub>) from the atmosphere are critical for environmental protection and public health. In this work, we employ quantum engineering approaches to explore the potential of metal-doped and vacancy-modified gallium sulfide monolayers (<strong>GaSML</strong>s) as reusable and sensitive SO₂ gas sensors. Using Grimme DFT-D approach, we systematically investigate the adsorption energies, charge transfer characteristics, electronic structure changes, work function modifications, and recovery times for SO₂ adsorption on pristine, vacancy-defective, and various metal-doped <strong>GaSML</strong> configurations. The adsorption energies calculated for <strong>GaSMLs</strong> (pristine and defective) range from −9.27 to −49.0 kcal/mol for sulfur-site modifications and from −3.0 to −9.59 kcal/mol for gallium-site modifications, demonstrating a wide range of adsorption capabilities that can be systematically modulated through defect engineering. Our results reveal that metal doping at sulfur sites, particularly with Mn, Cr, and Ni, significantly enhances SO₂ adsorption strength, charge transfer, and work function, accompanied by a notable narrowing of the band gap. These doped systems exhibit a balanced recovery time ranging from hundreds to thousands of seconds, suggesting practical reusability with mild external stimuli. Vacancy defects at sulfur sites also offer promising sensor performance with rapid desorption kinetics. Conversely, Fe doping, despite exhibiting the strongest adsorption, results in prohibitively long recovery times, limiting sensor applicability. This integrated analysis identifies Mn, Cr, and Ni-doped <strong>GaSML</strong>s as optimal candidates for high-performance, reusable SO₂ sensors, capable of efficient environmental SO₂ clearance. These findings provide valuable insights for the rational design of two-dimensional materials engineered at the quantum level for sustainable gas sensing and pollution control.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122894"},"PeriodicalIF":1.8,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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