Design of Colloidal Pt Catalysts Encapsulated by Silica Nano Membranes for Enhanced Stability in H2S Streams

Abstract

Poisoning of platinum catalysts by sulphur compounds is a significant problem that prevents their application in untreated gas streams. We introduce a novel concept to circumvent the poisoning problem by encapsulating individual platinum nano-particles with silica layers that act as selective membranes. Greatly enhanced sulfur tolerance for sufficiently dense illustrates the potential of our approach to design noble metal catalysts that survive in sulphur containing gas streams.

Nanostructured materials for applications in heterogeneous catalysis

“…137 This approach was also demonstrated by using a model catalyst based on silica beads decorated with Pt nanoparticles: the subsequent deposition of a mesoporous silica layer, used as a selective membrane, rendered the catalyst quite resistant against poisoning in H 2 S containing streams. 138 Other oxides can be added this way as well: in one example, titania was added to a Au/SiO 2 catalyst to create the Fig. 3 Example of changes in catalyst performance with average metal nanoparticle size in bimetallic samples.…”

Synthesis and thermal stability of ZrO2@SiO2 core–shell submicron particles

“…Core-shell nano-and microparticles represent a novel class of functional materials with numerous prospective applications. For example, they are well-suited for applications in catalysis, [1][2][3][4][5][6][7] high performance liquid chromatography, [8][9][10] as well as biomedical diagnosis and therapy. 6,7,[11][12][13][14][15] Furthermore, they are highly promising candidates for the development of advanced optical materials, which are needed, e.g., for thermophotovoltaic (TPV) systems, 16,17 photonic displays, 18 and structural coloration.…”

Observation and Characterization of the Surface Plasmon Resonances of Platinum Nanoshells

“…The products were centrifuged at 10,000 rpm for 10 min and redispersed in 30.0 mL of ethanol three times. 29 In order to modify the surfaces of SiO 2 hard templates with amino groups, 10.0 mL of SiO 2 nanospheres-dispersed ethanol and 5.0 mL of 1.0 M (3-aminopropyl)triethoxysilane (l, 98%)-dissolved ethanol were mixed and kept under stirring for 2 h. Then, the reaction mixture was added with 5.0 mL of platinum seeds-dispersed ethanol and stirred for 1 h to attach platinum seeds on SiO 2 nanospheres. For the transformation of platinum seeds into platinum shells, 4.0 mL of 2 days-aged 10 mM H 2 PtCl 6 (aq) and 2.0 mL of the above mixture were mixed, stirred for 1 h, added with 0.32 mL of 100 mM L-ascorbic acid(aq), and stirred for 1 h. 30 Finally, 10.0 mL of HF(aq) and 1.0 mL of the above colloid were mixed and stirred for 2 min.…”