Novel microfibrous‐structured silver catalyst for high efficiency gas‐phase oxidation of alcohols

Abstract

Novel microfibrous-structured silver catalysts were developed for gas-phase selective oxidation of mono-/aromatic-/di-alcohols. Sinter-locked three-dimensional microfibrous networks consisting of 5 vol % 8-lm-Ni (or 12-lm-SS-316L) fibers and 95 vol % void volume were built up by the papermaking/sintering processes. Silver was then deposited onto the surface of the sinter-locked fibers by incipient wetness impregnation method. At relatively low temperatures (e.g., 380C), the microfibrous-structured silver catalysts provided quite higher activity/selectivity compared to the electrolytic silver. The microfibrous Ag/Ni-fiber offered much better low-temperature activity than the Ag/ SS-fiber. The interaction at Ag particles and Ni-fiber interface not only visibly increased the active/selective sites of Ag þ ions and Ag n dþ clusters but also significantly promoted their low-temperature reducibility and ability for O 2 activation. In addition, the microfibrous structure provided a unique combination of large void volume, entirely open structure, high thermal conductivity and high permeability. V

Galvanic Deposition of Au on Paperlike Cu Fiber for High‐Efficiency, Low‐Temperature Gas‐Phase Oxidation of Alcohols

“…[20][21][22] The Au-3/Cu-fiber-200 catalyst also showed promising stability and good reactivity during a 50 h test at 220 8C ( Figure S1 in the Supporting Information) due to the excellent coking resistance compared to Ag/Ni-fiber systems. Our previously reported Ag/Ni-fiber catalysts could yield comparable conversion and selectivity, but only at temperatures of above 300 8C or above.…”

“…[9] A new class of thin-sheet sinter-locked metal-fiber supports have received increasing attention. [18][19][20][21][22] Indeed, our previous efforts have successfully demonstrated its special beneficial properties in the applications for strong endothermic NH 3 cracking, [18] methanol steam reforming, [19] and strong exothermic gas-phase selective oxidation of alcohols over a Ag/Ni-fiber catalyst. [15][16][17] The microfibrous structure is a promising tool for the development of high-performance catalysts, especially for strongly endothermic or exothermic reactions.…”

“…[15][16][17] This material is characterized by a special three-dimensional (3D) network, open structure, and high thermal conductivity. [20][21][22] More interestingly, such a microfibrous structure, with unique form factors, can be prepared as thin sheets (thickness: from submillimeter range to several millimeters) of large area and/or pleated sheet structure. [18][19][20][21][22] Indeed, our previous efforts have successfully demonstrated its special beneficial properties in the applications for strong endothermic NH 3 cracking, [18] methanol steam reforming, [19] and strong exothermic gas-phase selective oxidation of alcohols over a Ag/Ni-fiber catalyst.…”

“…[15][16][17] The microfibrous structure is a promising tool for the development of high-performance catalysts, especially for strongly endothermic or exothermic reactions. [15][16][17][18][19][20][21][22] Using this strategy, a novel catalyst system could be created, with a unique combination of excellent low-temperature activity and high-heat-transfer ability, if Au nanoparticles are easily and strongly embedded into the above-mentioned metallic microfibrous structure. [20][21][22] More interestingly, such a microfibrous structure, with unique form factors, can be prepared as thin sheets (thickness: from submillimeter range to several millimeters) of large area and/or pleated sheet structure.…”

High-performance SS-fiber@HZSM-5 core–shell catalyst for methanol-to-propylene: A kinetic and modeling study

“…Recently, microfibrous structured catalysts and reactors (MSCRs), as one primary kind of structured catalysts or catalytic reactors (SCRs), have been developed and applied in order to achieve the aim of process intensification in chemical industry, because MSCRs and other SCRs can be precisely designed in full detail up to the local surroundings of the catalyst, and the exact shape and size of all column internals are determined by pre-design and calculation rather than trial and error [35,36]. Therefore, these MSCRs exhibit great flexibility with respect to different length scales (e.g., diffusion lengths and voidage) and allow exceptionally large rates and selectivities [36,37], and have many significant functional advantages over the conventional catalysts and reactors, providing broad prospects in desulfuration [38,39], air filtration [40,41], H 2 fuel generation and cleanup [42][43][44][45], selective oxidation [46][47][48][49][50][51][52] and other fields [53][54][55][56], especially providing a new way of designing efficient catalysts and reactors for mass and/or heat transfer limited reactions [57]. In our previous studies [16,58], a new standing-free microfibrous-structured ZSM-5 zeolite catalyst was developed, being obtainable in a macroscopic scale by direct growth of the ZSM-5 zeolite crystals onto a three-dimensional (3D) porous network of sinter-locked metal microfibers.…”