Activated carbon supported silicotungstic acid catalysts for ethyl‐tert‐butyl ether synthesis

Abstract

in Wiley Online Library (wileyonlinelibrary.com).Vapor phase ethyl-tert-butyl ether (ETBE) production was conducted in the presence of Cesium salts of silicotungstic acid (Cs-STA), activated carbon supported silicotungstic acid (AC-STA), and activated carbon supported Cesium salts of silicotungstic acid (AC-Cs-STA) catalysts. Isobutene (IB) conversion to ETBE at 373 K were determined as 0.16 and 0.2 for STA and AC-STA catalysts on constant space time basis. This increase of activity is one of the highlights of this study considering that STA loading in AC-STA catalysts had been adjusted to 40%. IB conversion to ETBE obtained at 373 K in the presence of AC-STA catalyst was found to be close to equilibrium. Stability of the synthesized catalysts were tested by applying a washing procedure with ethanol. Repeated ETBE synthesis with thoroughly washed samples indicated quite stable and active catalyts.

Nitrogen-doped nanotubes-decorated activated carbon-based hybrid nanoarchitecture as a superior catalyst for direct dehydrogenation

“…57,58 Moreover, we can find that the D-band shifts from 1334 to 1347 cm −1 in comparison to that of the parent AC while there is almost no change for the G-band, which is ascribed to the effect of N-doping into the carbon matrix. [30][31][32][33][34][35][57][58][59][60] The larger I D /I G (the area ratio of D peak to G peak) of the N-doped AC-based hybrid structure (3.12) than that of AC (2.33) is an indicator of the more structural defects and lattice edges of the as-prepared hybrid composite, [61][62][63] but not for the more disordered amorphous carbon since the composite was prepared from AC through pyrolysis at 850 °C (less amorphous carbon but more graphitic carbon of the hybrid material than that of AC can be identified from the more intense G-band of the hybrid composite than that of AC). The in-plane crystallite size (La) of the N-doped AC-based hybrid nanostructure and the parent AC can be estimated by the following equation: 61,62 La (nm) = (2.4 × 10 − 10) λ 4 IJI D /I G ) −1 where λ is the Raman excitation wavelength (532 nm).…”

“…supported silicotungstic acid catalyst on AC, Pd/C, etc. [30][31][32][33][34][35] ACs have been employed as metalfree catalysts for various reactions including the oxidative dehydrogenation of hydrocarbons. [36][37][38][39] However, the depressed selectivity, low catalytic activity and poor stability limit their use as practical catalysts.…”

Highly Crystalline Mesoporous Phosphotungstic Acid: A High‐Performance Electrode Material for Energy‐Storage Applications

“…The shoulder peak at the O 1s spectra could be attributed to the presence of moisture on the surface of the sample. [20] The presence of phosphorous is also observed in all as-synthesized mPTA materials as shown in Figure S5 (see SI). [21] The O K-edge NEXAFS spectra of pristine PTA and 2.5-mPTA are exhibited in Figure S6 (see SI).…”

Highly Crystalline Mesoporous Phosphotungstic Acid: A High‐Performance Electrode Material for Energy‐Storage Applications

“…The decrease in W−O binding energy in 2.5‐mPTA might be attributed to the weakness of the W−O bonds upon connecting PTA clusters to form microchannels. The shoulder peak in the O 1s spectra could be attributed to the presence of moisture on the surface of the sample . The presence of phosphorus was also observed in all as‐synthesized mPTA materials (see Figure S5) …”