A nano-noble metal catalyst encapsulated by a metal-organic framework material and its preparation method and application

Abstract

The invention discloses a nano noble metal catalyst encapsulated by a metal organic framework material, and a preparation method and application of the nano noble metal catalyst. The nano noble metalcatalyst is composed of the following components in percentage by mass: 90-99.95% of a metal organic framework (MOF) carrier and 0.05-10% of a noble metal. The adopted preparation method is an impregnation-reaction method, the feed amount of materials in the preparation method is converted according to the composition of the components, and the feed amount is applied to a reaction for preparing n-butyl alcohol by dehydrogenation and condensation of ethyl alcohol. The preparation method of the catalyst provided by the invention is simple and efficient and has excellent performance. Continuous reaction for preparing butyl alcohol from ethyl alcohol through a fixed bed is adopted during the application, the flow is simple, the reaction condition is relatively mild, and the highest yield of the n-butyl alcohol in products can reach 25 wt%, and the catalyst has high stability.

Description

technical field [0001] The invention belongs to the technical field of catalytic chemistry, and in particular relates to a metal-organic framework (MOF)-encapsulated nano-Pd catalyst (Pd@MOF) and its preparation method and application. The catalyst can be used in the reaction of ethanol dehydrogenation condensation to produce n-butanol. Background technique [0002] Bio-based energy and chemicals can play an important role in coping with global climate change, implementing resource substitution strategies, ensuring energy security, and promoting the sustainable development of the chemical industry. As a renewable clean fuel, biomass ethanol has been widely used as a gasoline additive in Europe, the United States, Brazil and China. Although the addition of ethanol can reduce the amount of gasoline used, it has disadvantages such as low energy density, strong water absorption, and easy corrosion of the engine, so it is not an optimal gasoline blending component. Compared with...

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Problems solved by technology

[0003] In published literature, complex homogeneous catalysts such as iridium, ruthenium, and manganese have been used in the reaction of ethanol dehydrogenation and condensation to produce n-butanol, and have achieved high selectivity and yield of butanol, but their preparation is complicated. , use sodium hydroxide, sodium ethoxide and other soluble strong bases as catalysts in the aldol condensation step of acetaldehyde, especially in the use of tank reactors, the separation of catalysts is difficult, and the reaction cannot be carried out continuously, which is not conducive to the large-scale use of butanol fuel in the future Scale production [Dowson, G.R.M., Haddow, M.F., Wass, D.F., Catalytic conversion of ethanol into an advanced biofuel: unprecedented selectivity for n-butanol, Angew. Chem. Int. Ed., 2013, 52, 9005-9008; Chakraborty, S.P, Piszel, E.P., Cassandra, E.H., Jones, W.D., Highly selective formation of n-butanol from ethanol through the Guerbet process: A tandemcatalytic approach, J.Am.Chem.Soc., 2015, 137, 14264-14267; Wingad, R.L., Gates, P.J., Street, S.T.G., Wass, D.F., Catalytic conversion of ethanol to n-butanolusing ruthenium P-N Ligand complexes, ACS Catal., 2015, 5, 5822-5826; Fu S.M., ShaoZ.H., Wang Y.J., Liu Q.,Manganese-catalyzed upgrading of ethanol into 1-butanol.J.Am.Chem.Soc.,2017,139(34):11941-11948]

Solid catalysts such as hydrotalcite, apatite, strontium phosphate, alumina-loaded copper and nickel are used in the reaction of ethanol dehydrogenation condensation to prepare n-butanol, and there are also many public reports, but the yield of its butanol is generally low (generally lower than 10wt%), and the reaction temperature and pressure are high (>300°C,>4.0MPa) [Carvalho, D.L., de Avillez, R.R., Borges, L.E.P., Mg and Al mixed oxides and the synthesis of n-butanol from ethanol, Appl. Catal.A.,2012,415-416,96-100; Tsuchida,T.,Sakuma,S.,Takeguchi,T.,Ueda,W.,Yoshioka,T.,Reaction of ethanolover hydroxyapatite affected by Ca / P ratio of catalyst, J. Catal., 2008, 259, 183-189; OgO, S., Onda, A., Yanagisawa, K., Selective synthesis of 1-butanol from ethanolover strontium phosphate hydroxyapatite catalysts, Appl. Catal. A., 2011, 402,188-195; OgO,S.,Onda,A.,Yanagisawa,K.,Iwasa,Y.,Hara,K.,Fukuoka,A.,1-Butanolsynthesis from ethanol over strontium phosphate hydroxyapatite catalysts with various Sr / P ratios, J.Catal.,2012,296,24-30; Riittonen,T.,Toukoniitty,E.,Madnani,D.K.,Leino,A.R.Kordas.,One-pot liquid-phase catalytic conversion ofethanol to 1-butanol over aluminum oxide— the effect of the active metal on the selectivity, Catalysts, 2012, 2, 68-84; Dziugan, P., Jastrzabek, K.G., Binczarski, M., K arski,S.Continuous catalytic coupling of raw bioethanol into butanol and higher homologues,Fuel,2015,158,81-90; Jordison,T.L.,Lira,C.T.,Miller.D.J.,Condensed phase ethanol conversion to higher alcohols,Ind.Eng.Chem .Res.,2015,54,10991-11000; Riittonen,T.,Eranen,K.,Maki-Arvela,P.,Shchukarev,A.,Rautio,A.R.,Continuous liquid-phase valorization of bio-ethanol towards bio- butanolover metal modified aluminum, Renew. Energy, 2015, 74, 369-378]

Copper supported by cerium oxide with a large specific surface exhibits a high ethanol conversion rate of 67% and a butanol yield of 30% in a supercritical carbon dioxide medium (260 ° C, 10 MPa), but the reaction pressure of up to 10 MPa increases the reaction pressure. Requirements for equipment and its materials, and the production capacity of butanol per unit volume reactor is low, so its industrial application is also restricted to a certain extent [Earley J.H., BourneR.A., Watson M.J., Poliakoff M., Continuous catalytic upgrading of ethanol to n-butanol and>C4products over Cu / CeO2catalysts in supercritical CO2.GreenChem.,2015,17:3018-3025]

However, in the latest literature, activated carbon-supported copper-cerium oxide catalysts were used in the catalytic ethanol upgrading to butanol reaction, and achieved 46% ethanol conversion and nearly 20wt% butanol yield under relatively mild reaction conditions. rate, but its catalyst activity has a certain degree of decline in long-term evaluation[Jiang D.H., WuX.Y., Mao J., Ni J., Li X.N., Continuous catalytic upgrading ethanol to n-butanolover Cu-CeO2 / AC catalysts ,Chem.Commun.,2016,52:13749-13752; Activated carbon supported copper-metal oxide catalyst and its preparation method and application, Chinese invention patent, 201610399455.4]

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