- The effect of crystallinity on selectivity of palladium catalysts in hydrogenation of 2-ethyl-9,10-anthraquinone
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The catalytic properties of palladium crystallites obtained from various precursors were studied in the hydrogenation of 2-ethyl-9,10-anthraquinone. The highest yield of H2O2 (88percent) is achieved on unmodified Pd crystallites obtained from Pd(dba)2 at 50°C. A sigmoidal relationship between the coherent domain size (CDS) of Pd particles and the content of anthrones, which are by-products of the eAQ transformation, is established. Small Pd clusters, along with the reduction of eAQ carbonyl groups, accelerate predominantly the hydrogenation of the eAQH2 aromatic rings. The smallest contribution of the side processes is observed for a palladium catalyst with a CDS of 3–5 nm.
- Belykh, Lyudmila B.,Schmidt, Fedor K.,Skripov, Nikita I.,Sterenchuk, Tatyana P.
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- The effect of solvents on the rate of catalytic hydrogenation of 6-ethyl-1,2,3,4-tetrahydroanthracene-9,10-dione
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The rate of hydrogenation of 6-ethyl-1,2,3,4-tetrahydroanthracene-9,10- dione was investigated at 313 K and 0.1 MPa in 20 solvents. A multiple linear regression was used to describe the solvent effect. The regression of the reaction rates was carried out using two five-parameter linear regression models: the Abraham-Kamlet-Taft (AKT) and the Koppel-Palm (KP) model. After the elimination of the insignificant terms from the regression models, it was found that the basic character of the solvent and its Hildebrand cohesion energy density were the most important attributes influencing the hydrogenation rate. The analysis of both models led to the same conclusion. The resultant simplified AKT model gave closer fitting in comparison to the KP model. The results could facilitate the solvent selection for the industrial process of hydrogen peroxide production by the anthraquinone method with respect to the kinetics of anthraquinone hydrogenation.
- Fajt, Vojtech,Kurc, Ladislav,Cerveny, Libor
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- Mesoporous silica-supported Ni-B amorphous alloy catalysts for selective hydrogenation of 2-ethylanthraquinone
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The effects of pore structure on the reaction rates and selectivities in the liquid-phase hydrogenation of 2-ethylanthraquinone over Ni-B amorphous alloy catalysts prepared by the reductant-impregnation method were studied using regular (HMS, MCM-41, and
- Chen, Xueying,Wang, Shuai,Zhuang, Jihua,Qiao, Minghua,Fan, Kangnian,He, Heyong
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- The Effect of Particle Size and the Modifier on the Properties of Palladium Catalysts in the Synthesis of Hydrogen Peroxide by the Anthraquinone Method
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The effect of the composition of the catalytic system and the size of particles on the properties of palladium catalysts in 2-ethyl-9,10-anthraquinone hydrogenation was studied. It was shown that, depending on the nature of a reducing agent (H2, AlEt3), palladium species formed in the absence of a modifying agent catalyze various side processes to a substantial extent together with 2-ethyl-9,10-anthraquinone hydrogenation: mostly hydrogenolysis (in the case of H2 as a reducing agent) and hydrogenation of aromatic rings in 2-ethyl-9,10-anthrahydroquinone (in the case of AlEt3 as a reducing agent). Elementary phosphorus was found to have a promoting effect on the selectivity of palladium catalysts in the synthesis of hydrogen peroxide by the anthraquinone method. The main factors that make it possible to control the selectivity of palladium catalysts were discussed.
- Belykh, L. B.,Gvozdovskaya, K. L.,Sanzhieva, S. B.,Schmidt, F. K.,Skripov, N. I.,Sterenchuk, T. P.
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p. 585 - 592
(2018/10/02)
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- Hydrogenation of 2-ethylanthraquinone over Pd/poly(4-vinylpyridyne) catalysts
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Polymer, namely poly(4-vinylpyridyne) (PVP) was used as a support for palladium catalysts acting in liquid phase hydrogenation of 2-ethylanthraquinone (eAQ), a key step in industrial production of hydrogen peroxide. The catalytic hydrogenation was carried out in a slurry reactor at atmospheric pressure of H2 and temperature 43°C. The progress of eAQ hydrogenation over Pd/PVP catalyst was the same as observed earlier in the presence of Pd/SiO2. In initial stage of reaction eAQ was reduced with high selectivity to eAQH2 (2-ethylanthrahydroquinone). In the further process termed "deep hydrogenation" hydrogenation of aromatic rings (formation of tetrahydroanthrahydroquinone H4eAQH2) and hydrogenolysis of carbon-oxygen bonds (formation of degradation products) in eAQH2 proceeded. It was stated that in the presence of mass transport limitations the progress of reactions leading to the formation of "degradation products" was intensive.
- Drelinkiewicz, Alicja
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p. 109 - 119
(2007/10/03)
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- The Influence of the Method of Pd/SiO2 Catalyst Reduction on the Course of 2-Ethylanthraquinone Hydrogenation
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Hydrogenation of 2-ethylanthraquinone (eAQ) was carried out over 4percent Pd/SiO2 catalyst under the stirred batch reactor conditions at atmospheric pressure of hydrogen and temp. 62 deg C.Catalysts containing the hydrated palladium oxide were reduced with hydrogen in situ or outside of the reactor using formaldehyde, hydrazine or hydrogen (at temp. 50-300 deg C).It was stated that the method of catalyst pretreatment influences both the course of >C=O to C-OH reduction and the "deep hydrogenation"comprising hydrogenation of aromatic rings as well as hydrogenolysis of carbon-oxygen bond.The highest rate of >C=O reduction and the high selectivity of this reaction was observed over catalyst reduced in situ.At the presence of such a catalyst also the selectivity of 2-ethyl-5,6,7,8-tetrahydroantraquinone (H4eAQ) formation in "deep hydrogenation" was relatively high (50percent).Key words: anthraquinone method, deep hydrogenation, activity and selectivity of catalysts.
- Drelinkiewicz, Alicja
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