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- Bernardini, A., et al.
(author)
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Direct synthesis of H2O2 over Pd supported on rare earths promoted zirconia
- 2015
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In: Catalysis Today. - : Elsevier BV. - 0920-5861 .- 1873-4308. ; 256, s. 294-301
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Journal article (peer-reviewed)abstract
- In this work Pd (0.3 or 0.6 wt.%) was supported on both ZrxM1-xO2 (M = La, Y, Ce) and on mechanical mixtures of CeO2 and ZrO2. The synthesized catalysts were characterized by XRD, TPR, AAS and CO chemisorption and tested for the direct synthesis of hydrogen peroxide in a high pressure semibatch apparatus. The reactants conversion was limited in order to avoid mass-transfer limitations. No selectivity enhancers of any kind were used and the all the materials were halide free. Small metal particles were obtained (1-2.6 nm). Supports with smaller pore diameters leaded to larger Pd particles, which in turn were found to preferentially support the formation of the peroxide. Moreover, supports with higher reducibility favored the production of H2O2, probably due to an easier reduction of the active metal, essential to achieve high selectivity. Notwithstanding the absence of enhancers, the specific activity and selectivity recorded were very high.
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| 2. |
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| 3. |
- Rogne, Per, et al.
(author)
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Real-time 31P NMR investigation on the catalytic behavior of the enzyme Adenylate kinase in the matrix of a switchable ionic liquid
- 2015
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In: ChemSusChem. - : John Wiley & Sons. - 1864-5631 .- 1864-564X. ; 8:2, s. 3764-3768
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Journal article (peer-reviewed)abstract
- The integration of highly efficient enzymatic catalysis with the solvation properties of ionic liquids for an environmentally friendly and efficient use of raw materials such as wood requires fundamental knowledge about the influence of relevant ionic liquids on enzymes. Switchable ionic liquids (SIL) are promising candidates for implementation of enzymatic treatments of raw materials. One industrially interesting SIL is constituted by monoethanol amine (MEA) and 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) formed with sulfur dioxide (SO2) as the coupling media (DBU-SO2-MEASIL). It has the ability to solubilize the matrix of lignocellulosic biomass while leaving the cellulose backbone intact. Using a novel 31P NMR-based real-time assay we show that this SIL is compatible with enzymatic catalysis because a model enzyme, adenylate kinase, retains its activity in up to at least 25 wt % of DBU-SO2-MEASIL. Thus this SIL appears suitable for, for example, enzymatic degradation of hemicellulose.
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