Controlled nitridation of tantalum (oxy)nitride nanoparticles towards optimized metal-support interactions with gold nanocatalysts

Abstract

Graphic abstractOptimized metal-support interactions was achieved on ionothermally prepared tantalum (oxy)nitrides with controlled nitridation, and the as-formed Au δspecies promoted by TaON are efficient for nitrobenzene hydrogenation due to its moderated adsorption of substrates.The electron regulation on supports can vary metal-support interactions with loaded metals in heterogeneous catalysis. In this paper, a facile Sr 2+ -mediated ionothermal route was introduced to control the nitridation degree in tantalum (oxy)nitrides, resulting in varied electronic properties and optimized interactions with gold nanocatalysts. A new mechanism was proposed that the formation of SrTa4O11 intermediates facilitated the replacement of O by N in controlled nitridation, and more importantly avoided undesired over-nitridation. As expected, the TaON support with defined nitridation promoted electronic metal-support interactions to generate Au δspecies, which was highly active for the thermal hydrogenation of nitrobenzene due to the moderated adsorption and effective activation on Au δin Au/TaON. This work elucidated the optimized metal-support interactions achieved on controllably nitridated supports, opening up new opportunities for the development of efficient nanocatalysts.

Enhancing Metal–Support Interactions by Molybdenum Carbide: An Efficient Strategy toward the Chemoselective Hydrogenation of α,β‐Unsaturated Aldehydes

“…As further validated by XPS (Figure b), the Ir 4f 7/2 and 4f 5/2 peaks in Ir/Mo 2 C are red shifted to 60.3 and 63.2 eV, respectively, in comparison with those of metallic Ir (Ir 4f 7/2 =60.9 eV, Ir 4f 5/2 =63.9 eV) on inert SiO 2 . This observation well indicates the negatively charged Ir (Ir δ− ) on the Mo 2 C surface …”

“…As furtherv alidated by XPS (Figure 2b), the Ir 4f 7/2 and 4f 5/2 peaks in Ir/Mo 2 C are red shifted to 60.3 and 63.2 eV,r espectively,i nc omparison with those of metallic Ir (Ir 4f 7/2 = 60.9 eV,I r4f 5/2 = 63.9 eV) [39,40] on inert SiO 2 .T his observation well indicates the negatively chargedI r( Ir dÀ )o nt he Mo 2 Cs urface. [41] Generally,t he variation in the work functions of metals and supports usually contributes to the electronic metal-support interactions in heterogeneousc atalysts. [29,30] Owing to the lower work function of Mo 2 C( 5.00 eV) than that of Ir (5.22 eV), [42,43] the formation of Ir dÀ on Mo 2 Cshould be ascribed to the charget ransfer through the interfaces.Wefurther examined the charge redistribution of Ir on Mo 2 Ca nd SiO 2 supports by using periodic spin-polarized calculations in the framework of density functional theory (DFT) implemented within the Vienna ab initio simulationp rogram (VASP).…”

Tantalum Nitride Electron‐Selective Contact for Crystalline Silicon Solar Cells

“…The XPS survey spectra of the TaN x thin films in the binding energy range 0-1200 eV, presented in Figure S1 in the Supporting Information, show the presence of Ta, O, N, and C signals. [38][39][40][41] The calculated Ta atomic percentages of TaN x , TaO x N y , and TaO x are 76.0%, 14.2%, and 9.8%, respectively. Figure 2 shows the XPS core-level spectra of Ta 4f and N 1s for the TaN x films.…”

Hydrogen Doping into MoO3 Supports toward Modulated Metal–Support Interactions and Efficient Furfural Hydrogenation on Iridium Nanocatalysts

“…Metal oxides serve as important supports for noble metals in heterogeneous catalysis, and reducible metal oxides (e.g., MoO 3 , WO 3 , Fe 2 O 3 , Co 3 O 4 , TiO 2 ) in particular have attracted special attention because of their variable valence states and relatively easy reduction during catalysis or catalyst preparation . As such supports are hydrogen doped, the resulting hydrogenated metal oxides present abundant oxygen vacancies, M−OH and M−H on the surface, and more importantly, tunable band states with metallic features, which will further affect the size, morphology, valence state, and catalytic behavior of loading metals as a result of enhanced metal–support interactions . Among them, hydrogenated molybdenum oxides (H−MoO x ) are worth highlighting owing to the promoted acidity and the tailored electronic configuration after hydrogen doping (H doping), with special regard to the various valence states of Mo (+6, +5, +4, +3, +2, and 0) .…”

“…[1][2][3][4][5] As such supportsa re hydrogen doped, the resulting hydrogenated metal oxides present abundant oxygen vacancies, MÀOH and MÀHo nt he surface, and more importantly,t unable band states with metallic features, [6][7][8] which will furthera ffect the size, morphology,v alence state, and catalytic behavior of loading metals as ar esult of enhanced metal-support interactions. [3,9,10] Amongt hem, hydrogenated molybdenumo xides (HÀMoO x )a re worth highlighting owing to the promoted acidity and the tailored electronic configuration after hydrogen doping (H doping), with special regard to the various valence states of Mo (+ 6, + 5, + 4, + 3, + 2, and 0). [11][12][13][14] For example, the improved acidityo nH ÀMoO x can acceleratea cid-catalyzed ring-opening and cyclization processes, therebye nabling synergy toward the selective hydrogenationo fb iomass-derived oxygenates.…”