In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 ...In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 molecules using scanning tunneling microscopy and density function theory calculations.Pt single atoms were prepared on the TiO2(110)surface at 80 K,showing their preferred adsorption sites at the oxygen vacancies.We characterized the adsorption configurations of CO and O2 molecules separately to the TiO2-supported Pt single atom samples at 80 K.It is found that the Pt single atoms tend to capture one CO to form Pt-CO complexes,with the CO molecule bonding to the fivefold coordinated Ti(Ti5 c)atom at the next nearest neighbor site.After annealing the sample from 80 K to 100 K,CO molecules may diffuse,forming another type of complexes,Pt-(CO)2.For O2 adsorption,each Pt single atom may also capture one O2 molecule,forming Pt-O2 complexes with O2 molecule bonding to either the nearest or the next nearest neighboring Ti5c sites.Our study provides the single-molecule-level knowledge of the interaction of CO and O2 with Pt single atoms,which represent the important initial states of the reaction between CO and O2.展开更多
Topological materials have attracted extensive attention in condensed matter physics because of their exotic physical properties and promising potential applications.If the bulk gap of an insulator closes at certain n...Topological materials have attracted extensive attention in condensed matter physics because of their exotic physical properties and promising potential applications.If the bulk gap of an insulator closes at certain nodal points or lines in the Brillouin zone(BZ),the resultant gapless phase is known as the topological semimetal(TSM)[1].Dirac nodal line semimetals(DNLSMs)[2,3]have been sought as novel quantum materials presenting quantum anomalies[4,5].The DNLSMs against spin-orbit coupling(SOC)were discovered in several three-dimensional(3D)bulk materials[6–8].Flourishing two-dimensional(2D)van der Waals(vdW)materials are,in comparison with their 3D counterparts,easier to experimentally measure and manipulate.However,2D materials have one less dimension of translation symmetry operation,and the corresponding symmetry operations and groups are significantly reduced,narrowing the range of candidate structures.展开更多
基金supported by the National Natural Science Foundation of China(No.21972129)the Ministry of Science and Technology of China(2016YFA0200603)Anhui Initiative in Quantum Information Technologies(AHY090000)。
文摘In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 molecules using scanning tunneling microscopy and density function theory calculations.Pt single atoms were prepared on the TiO2(110)surface at 80 K,showing their preferred adsorption sites at the oxygen vacancies.We characterized the adsorption configurations of CO and O2 molecules separately to the TiO2-supported Pt single atom samples at 80 K.It is found that the Pt single atoms tend to capture one CO to form Pt-CO complexes,with the CO molecule bonding to the fivefold coordinated Ti(Ti5 c)atom at the next nearest neighbor site.After annealing the sample from 80 K to 100 K,CO molecules may diffuse,forming another type of complexes,Pt-(CO)2.For O2 adsorption,each Pt single atom may also capture one O2 molecule,forming Pt-O2 complexes with O2 molecule bonding to either the nearest or the next nearest neighboring Ti5c sites.Our study provides the single-molecule-level knowledge of the interaction of CO and O2 with Pt single atoms,which represent the important initial states of the reaction between CO and O2.
基金financial support from the Ministry of Science and Technology(MOST)of China(2018YFE0202700,2017YFA0302903,and 2019YFA0308603)the National Natural Science Foundation of China(11622437,61674171,61761166009,11574392,11974421,11974422,11774422,12174443,and 12134020)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB30000000)the Fundamental Research Funds for the Central Universities,and the Research Funds of Renmin University of China(22XNKJ30(W.J.)and 21XNH090(D.P.G.))。
文摘Topological materials have attracted extensive attention in condensed matter physics because of their exotic physical properties and promising potential applications.If the bulk gap of an insulator closes at certain nodal points or lines in the Brillouin zone(BZ),the resultant gapless phase is known as the topological semimetal(TSM)[1].Dirac nodal line semimetals(DNLSMs)[2,3]have been sought as novel quantum materials presenting quantum anomalies[4,5].The DNLSMs against spin-orbit coupling(SOC)were discovered in several three-dimensional(3D)bulk materials[6–8].Flourishing two-dimensional(2D)van der Waals(vdW)materials are,in comparison with their 3D counterparts,easier to experimentally measure and manipulate.However,2D materials have one less dimension of translation symmetry operation,and the corresponding symmetry operations and groups are significantly reduced,narrowing the range of candidate structures.
