Monolithic fiber/foam-structured catalysts: beyond honeycombs and micro-channels

ABSTRACTHeterogeneous catalysis plays a pivotal role in the current chemical and energy vectors production. Notably, to fully utilize the intrinsic activity and selectivity of a catalyst, the chemical reactor has to be designed and operated optimally to achieve enhanced heat/mass transfer, well-defined contact time of reactants, uniform flow pattern, and high permeability. Structured catalysts are a promising strategy to overcome the major drawbacks encountered in the traditional packed-bed reactor technology due to the improved hydrodynamics in combination with enhanced heat/mass transfer. Newly emerged fiber/foam-substrates, with an entirely open 3D network structure, bring distinct advantages over the honeycomb and micro-channel contacting methods, including free radial diffusion, eddy-mixing driven heat/mass transfer, large area-to-volume ratio, and high contacting efficiency. However, how to place the nanocatalysts onto the fiber/foam-substrates is a challenging problem because the commercial washcoating method has great limitations such as the nonuniformity and easy exfoliation of coatings. This review discusses the newly developed non-dip-coating methods for the fiber/foam-structured catalysts and their promising applications in the strongly exo-/endo-thermic and/or high throughput reaction processes.KEYWORDS: Catalytic distillationcatalytic functionalizationelectrocatalysisenvironmental protectionfiberfoamheat/mass transferheterogeneous catalysishydrogenationmonolithic catalystnon-dip-coatingoxidationprocess intensificationreformingstructured catalystsupercapacitorssyngas conversion AcknowledgmentsThis work was supported by the National Natural Science Foundation of China (grants 22272053, 22179038, 22072043, 21773069, 21703069, 21473057, U1462129, 21273075, 21076083, 20973063, 20590366, 20573036), the Shanghai Municipal Science and Technology Commission (grants 21DZ1206700, 18JC1412100, 210HQ1400800, 05QMX1418, 05DJ14002), the "973 Project" (grant 2011CB201403), and "863 Project" (grant 2007AA05Z101) from the Ministry of Science and Technology of the People's Republic of China, the Ministry of Education of the People's Republic of China (grants 20090076110006, NCET-06-0423), and the Research Funds of Happiness Flower ECNU (2020ST2203).Disclosure statementNo potential conflict of interest was reported by the author(s).