A Sacrificial Coating Strategy Toward Enhancement of Metal–Support Interaction for Ultrastable Au Nanocatalysts

Abstract

Supported gold (Au) nanocatalysts hold great promise for heterogeneous catalysis; however, their practical application is greatly hampered by poor thermodynamic stability. Herein, a general synthetic strategy is reported where discrete metal nanoparticles are made resistant to sintering, preserving their catalytic activities in high-temperature oxidation processes. Taking advantage of the unique coating chemistry of dopamine, sacrificial carbon layers are constructed on the material surface, stabilizing the supported catalyst. Upon annealing at high temperature under an inert atmosphere, the interactions between support and metal nanoparticle are dramatically enhanced, while the sacrificial carbon layers can be subsequently removed through oxidative calcination in air. Owing to the improved metal-support contact and strengthened electronic interactions, the resulting Au nanocatalysts are resistant to sintering and exhibit excellent durability for catalytic combustion of propylene at elevated temperatures. Moreover, the facile synthetic strategy can be extended to the stabilization of other supported catalysts on a broad range of supports, providing a general approach to enhancing the thermal stability and sintering resistance of supported nanocatalysts.

Enhancing Light-Driven Production of Hydrogen Peroxide by Anchoring Au onto C3N4 Catalysts

“…The product was a yellow powder. The Au/C 3 N 4 -250 catalyst was synthesized by a method similar to the literature [32]. Briefly, the pH value of an aqueous solution (0.02 g HAuCl 4 ·3H 2 O in 60 mL water) was adjusted to 10.0 by adding 1 M NaOH.…”

“…The Au particles had a narrower size distribution on the Au/C 3 N 4 -500(N 2 ) than on the Au/C 3 N 4 -500(Air). The high-resolution transmission electron microscopy photographs showed that the distance of the neighboring planes was 0.235 nm in both catalysts, corresponding to the d-spacing of the plane (111) in Au [32]. Au particles had more crystal defects on the Au/C 3 N 4 -500(N 2 ) (Figure 1c) than on the Au/C 3 N 4 -500(Air) (Figure 1f).…”

“…Generally, when the size of the metal particles is greater than 7 nm, the activity drops sharply [31]. However, the smaller-sized metal particles possess a low Tammann temperature and high surface energy, leading to low thermal stability and the sintering phenomenon when heated [32]. In this article, we investigated Au-supported C 3 N 4 prepared by a stabilized method.…”

Co‐Template Directed Synthesis of Gold Nanoparticles in Mesoporous Titanium Dioxide

“…Thermal treatment at elevated temperatures is often necessary to achieve optimal Au/TiO 2 interfaces. However, such thermal treatment can cause the overgrowth of TiO 2 crystallite grains and the aggregation of AuNPs, both of which are known to be detrimental to the photocatalytic activity of these nanocomposite materials …”

Mesoporous Co‐Al oxide nanosheets as highly efficient catalysts for CO oxidation

“…K E Y W O R D S CO oxidation, Co-Al oxide, mesoporous nanosheet, stable catalyst 1 | INTRODUCTIONThe oxidation of carbon monoxide (CO) over heterogeneous catalysts is of great importance due not only to the practical applications in automotive gas treatment, indoor air cleaning, and CO removal from H 2 feed gas for fuel cells, but also to its use as a model reaction in laboratory research. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Up to now, many highly efficient catalysts for CO oxidation, mainly including supported noble metals (such as Au and Pt) 8,9,11,12,[19][20][21][22][23][24][25] and metal-oxides (such as Co 3 O 4 and MnO 2 ) have been successfully developed. 7,[13][14][15][16][17][18][26][27][28][29][30][31][32][33] For example, TiO 2 -supported Au catalyst is very active for CO oxidation at the temperature of −70 C. 1...…”