Thermal Stability of Tungsten Oxide Clusters

Regulating the Selective Dispersion of Tungsten Oxide to Promote Propane Combustion on Pt-Nanoparticle Catalysts Supported on WOx/ZrO2 by Tuning the Zirconia Crystal Phase

“…37.9 and 35.9 eV assigned to the W 4f 5/2 and 4f 7/2 peaks, respectively, which indicate the dominant presence of the W 6+ species on the surface. 35,44 The W 4f spectra of the WO x /ZrO 2 supports in Figure S6 show that the BE of W 4f 7/2 on WO x /t-ZrO 2 was obviously lower than that of WO x /m-ZrO 2 , demonstrating the existence of less positive W species (W x+ x < 6) on the surface of WO x /t-ZrO 2 . However, the loading of Pt promotes W 4f of WO x /t-ZrO 2 to obviously shift to higher BE, suggesting the electron transfer from WO x species to Pt via strong electronic interactions, which facilitates the formation of more metallic Pt 0 accompanying the increase of the chemical valence of W. In contrast, nearly the same W 4f spectra with the typical BE of W 6+ on WO x /m-ZrO 2 and Pt/WO x /m-ZrO 2 indicate the weak interaction between Pt and WO x species on Pt/WO x /m-ZrO 2 .…”

“…Meanwhile, it is very convenient to realize the surface acid functionalization of ZrO 2 via the modification of acidic additives, such as sulfate ions, MoO 3 , VO x , Nb 2 O 5 , etc. − Among them, WO x is also a common acidic additive used for surface modification of ZrO 2 to adjust its surface acidity, which can also be used to promote propane oxidation over Pt-based catalysts. − For instance, Yoshida’s group first studied the effect of the additives on the supported platinum catalyst for propane oxidation, and they reported that the catalytic activity was particularly enhanced by the addition of tungsten . Zhu et al found that the turnover frequency (TOF) of propane combustion on Pt/5WO x /ZSM-5 was 35 times higher than that of the catalyst without WO x .…”

Structural and Electronic Properties of a W3O9Cluster Supported on the TiO2(110) Surface

“…1 Among these TMOs, tungsten oxide (WO x ) has been focused on in many studies because it possesses the strongest Brønsted acid sites. [2][3][4][5] Various substrates have been used for the preparation of supported tungsten oxide species including Si, 6 SiO 2 /Mo(112), 7 TiO 2 , [8][9][10][11][12] Al 2 O 3 , 13 SiO 2 , 14 and ZrO 2 ; [15][16][17][18][19][20] the experimental results indicate that the structure and catalytic properties of WO x are strongly influenced by the support. 21 To understand the nature of the interaction between the support and WO x , which is directly related to the catalytic activity, the preparation of monodispersed WO x clusters with well-defined structure is a key step since they are the most suitable models for investigating the structure-reactivity relationships of this particularly important class of TMOs.…”

“…The supported early transition metal oxides (TMOs) with pentavalent and hexavalent cations are an important family of catalysts used in the petrochemical and refining industry to catalyze many reactions, such as oxidative dehydrogenation of hydrocarbons, partial oxidation of alcohols, and selective reduction of NO x . Among these TMOs, tungsten oxide (WO x ) has been focused on in many studies because it possesses the strongest Brønsted acid sites. − Various substrates have been used for the preparation of supported tungsten oxide species including Si, SiO 2 /Mo(112), TiO 2 , − Al 2 O 3 , SiO 2 , and ZrO 2 ; − the experimental results indicate that the structure and catalytic properties of WO x are strongly influenced by the support . To understand the nature of the interaction between the support and WO x , which is directly related to the catalytic activity, the preparation of monodispersed WO x clusters with well-defined structure is a key step since they are the most suitable models for investigating the structure−reactivity relationships of this particularly important class of TMOs.…”

On-Demand Activation of Photochromic Nanoheaters for High Color Purity 3D Printing

“…One of the most promising of these materials is tungsten­(VI) oxide, WO 3 , which has a strong absorption in the NIR that can be efficiently switched on and off using electricity (electrochromic) or ultraviolet radiation (photochromic) . Moreover, WO 3 is stable at high temperatures well above 400 °C , and can be readily synthesized as nanoparticles using cheap reactants. , In this work, we utilize for the first time the photochromic properties of WO 3 NPs to develop a 3D printing method that offers very high color purity and achieves white 3D printed objects via photothermal sintering with low cost NIR light sources.…”