Role of Pt Loading in the Photocatalytic Chemistry of Methanol on Rutile TiO2(110)

Hao, Qunqing1,2; Wang, Zhiqiang1,3; Wang, Tianjun1; Ren, Zefeng1; Zhou, Chuanyao1; Yang, Xueming1,4

2019-01

10.1021/acscatal.8b03359

ACS Catalysis   影响因子和分区

2155-5435

As a cocatalyst, Pt is well-known for accepting photoexcited electrons and lowering the overpotential of hydrogen production in photocatalysis, being responsible for the enhanced photocatalytic efficiency. Despite the above existing knowledge, the adsorption of reactants on the Pt/photon-absorber (for example, Pt/TiO2) interface, a prerequisite to understand the photocatalytic chemistry, is extremely difficult to investigate mainly because of the complexity of the powdered material and solution environment. Combining ultrahigh vacuum and well-ordered single crystals, we study the photocatalytic chemistry of methanol on Pt-loaded rutile TiO2(110) using temperature-programmed desorption (TPD) and ultraviolet photoelectron spectroscopy (UPS). Despite the same photocatalytic chemical products (i.e., formaldehyde and surface hydrogen species) as on Pt-free TiO2(110), the subsequent chemistry of surface hydrogen species and the photocatalytic reaction rate are much different. The bridging hydroxyls desorb as water molecules around 500 K on the Pt-free TiO2(110) surface, and by contrast, this desorption channel disappears completely and water and molecular hydrogen desorb at much lower temperature (<300 K) after Pt deposition, which can prevent the recombination of hydrogen species with formaldehyde. More importantly, methanol dissociates into methoxy at the Pt/TiO2(110) interface, which is crucial in the photocatalytic chemistry of methanol on TiO2 surfaces because methoxy is a more effective hole scavenger than methanol itself. The photocatalytic chemical reaction rate is increased by nearly 1 order of magnitude after 0.12 monolayer Pt deposition. This work suggests that Pt loading can promote the dissociation of methanol into methoxy and lower the desorption barrier of molecular hydrogen, which may work cooperatively with separating photoexcited charges to enhance the photocatalytic efficiency. Our work implies the importance of the cocatalysts in affecting the surface structure and adsorption of reactants and products and then improving the photoactivity, in addition to the well known role in charge separation.

Pt cocatalyst titanium dioxide hydrogen production charge separation methanol to methoxy conversion

SCI ; EI

英语

通讯

Youth Innovation Promotion Association of CAS[2017224]

Chemistry

Chemistry, Physical

WOS:000455286600031

AMER CHEMICAL SOC

20190206361901

Deposition ; Efficiency ; Formaldehyde ; Hydrogen production ; Methanol ; Molecules ; Oxide minerals ; Reaction rates ; Separation ; Single crystals ; Temperature programmed desorption ; Titanium dioxide ; Ultraviolet photoelectron spectroscopy

Minerals:482.2 ; Gas Fuels:522 ; Chemical Reactions:802.2 ; Chemical Operations:802.3 ; Organic Compounds:804.1 ; Inorganic Compounds:804.2 ; Production Engineering:913.1 ; Atomic and Molecular Physics:931.3 ; Crystalline Solids:933.1

Web of Science

1.Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Mol React Dynam, 457 Zhongshan Rd, Dalian 116023, Liaoning, Peoples R China
2.Sci & Technol Surface Phys & Chem Lab, POB 9-35, Jiangyou 621908, Sichuan, Peoples R China
3.Xidian Univ, Sch Phys & Optoelect Engn, Xian 710071, Shaanxi, Peoples R China
4.Southern Univ Sci & Technol, Dept Chem, 1088 Xueyuan Rd, Shenzhen 518055, Guangdong, Peoples R China

Hao, Qunqing,Wang, Zhiqiang,Wang, Tianjun,et al. Role of Pt Loading in the Photocatalytic Chemistry of Methanol on Rutile TiO2(110)[J]. ACS Catalysis,2019,9(1):286-294.

Hao, Qunqing,Wang, Zhiqiang,Wang, Tianjun,Ren, Zefeng,Zhou, Chuanyao,&Yang, Xueming.(2019).Role of Pt Loading in the Photocatalytic Chemistry of Methanol on Rutile TiO2(110).ACS Catalysis,9(1),286-294.

Hao, Qunqing,et al."Role of Pt Loading in the Photocatalytic Chemistry of Methanol on Rutile TiO2(110)".ACS Catalysis 9.1(2019):286-294.