Furfural Oxidation with Hydrogen Peroxide Over ZSM-5 Based Micro-Mesoporous Aluminosilicates

Micro-mesoporous aluminosilicates based on ZSM-5 zeolite, obtained by a dual template method, as well as in the presence of a dual-functional template (i.e. a Gemini-type surfactant), were tested in the oxidation of furfural with hydrogen peroxide. Even substantial changes in acidity and porosity of the catalysts result in minor variations of selectivity towards the desired products. Application of the synthesized zeolite-based materials in the oxidation of furfural with hydrogen peroxide leads to formation of 2(5H)-furanone (yield up to 28.5%) and succinic acid (up to 19.5%) as the main C4 reaction products. The kinetic model developed previously to treat the results for oxidation of furfural over sulfated zirconia was able to describe the data also for micro-mesoporous aluminosilicates.

Graphical Abstract

     

Production of a fluidized bed moving along an inclined gas-distributing grid

Results are presented from analytical and experimental studies on how the height of a fluidized bed is dependent on the major parameters when it moves up an inclined gas-distributing grid.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 46, No. 2, pp. 261–264, February, 1984.     

Experimental Investigation of a Piezo-Optical Transducer for Highly Sensitive Strain Gauges

The characteristics of a piezo-optical transducer of a new design with high strain sensitivity at compact size have been studied.The original form of the photoelastic element provides a considerable increase in the stress in its working area at a given external force, resulting in an increase in the sensitivity of the transducer. The main characteristics of the transducer were measured using a specially designed device. The strain at a given applied force was calculated using a developed mathematical model of the transducer. As a result, the sensitivity to the relative strain was Δx/x=3 · 10^?10, the dynamic range was at least four orders of magnitude higher and the gauge factor three orders of magnitude higher than those of strain-resistive gauges.     

Template synthesis,structure, sorption properties and acidity of micro-mesoporous materials obtained from sol-precursor of zeolite BEA

Partially zeolitized micro-mesoporous materials (the total specific surface area S _BET  = 460–645 m²/g, mesopore volume V _meso  = 0.30–0.57 cm³/g, mesopore diameter D _meso  ≈ 5.6 nm, micropore volume V _micro  = 0.11–0.16 cm³/g, micropore diameter D _micro  ≈ 0.72 nm) and X-ray amorphous micro-mesoporous materials with uniform mesoporous structure (mesopore specific surface area S _meso  = 820–890 m²/g, total pore volume V _t  = 0.71–0.86 cm³/g, V _meso  = 0.53–0.67 cm³/g, D _meso  = 1.8–2.4 nm) were obtained by micellar templating of sol-precursor containing primary products of crystallization of zeolite BEA under conditions typical for forming of mesoporous molecular sieve MCM-41 (hydrothermal treatment at 100–130 °C for 3–5 days). It was found that the obtained X-ray amorphous micro-mesoporous materials contain secondary building units of zeolite BEA (five-membered rings of Si–O tetrahedra of BEA) and show acidic properties comparable to zeolite BEA.