Acetaldehyde, adsorption

An I6C and TA study of acetaldehyde adsorption on activated carbons Y. El-Sayed and T. J. Bandosz... 

Fig. 4. Difference in DTG curves after and before acetaldehyde adsorption for BAX carbons.

El-Sayed, Y. and Bandosz, T.J. (2002). Acetaldehyde adsorption on nitrogen-containing activated carbons. Langmuir, 18, 3213-18. 

Figure 3 and Table 2 present the desorption products during TPD after acetaldehyde adsorption on UO2 (Fl2-reduced UO3). 

Carbon yield and carbon selectivity of products formed during TPD after acetaldehyde adsorption at room temperature on UO2... 

Formation of acetaldehyde via reaction of acetylene and water over Cd-exchanged phillipsite, mordenite, clinoptilolite, erionite, chabazite, and zeolites A, X and Y was investigated by the group of Kallo [907,908], while acetaldehyde adsorption on H-ZSM-5 was studied via FTIR by Diaz et al. [909], which indicated proton transfer with formation of crotonaldehyde and subsequent dehydration. At pressures higher than 400 Pa oligomerization occurred. 

El-Sayed and Bandosz used three activated carbon samples of different origin, namely BPL from Calgon and MVP from Norit, both prepared from bituminous coal, and BAX from Westvaco, made from wood, using chemical activation with phosphoric acid for the adsorption of acetaldelyde. These carbons were washed in a soxhlet apparatus to remove water-soluble impurities and then oxidized with nitric acid. The adsorption of acetaldehyde was determined by inverse gas chromatography at infinite dilution and finite concentration. The heats of acetaldehyde adsorption at... 

H. Wang, Z. Jusys, R.J. Behm, Ethanol and acetaldehyde adsorption on a carbon-supported Pt catalyst a comparative DEMS study, Euel Cells 4 (2004) 113-125. 

Pt is able to break the C—C bond, leading to adsorbed CO species at relatively low anode potentials from 0.3 V RHE, the adsorbed peak has clearly been shown in SNIFTIRS spectrum [55]. One can consider two distinct sequences steps 7 and 8 or steps 9 and 10. The first sequence assumes that ethanol must be adsorbed by the C—H bond cleavage in both carbon atoms and the second sequence assumes that the rupture of the C—H bond of the intermediate formed after the acetaldehyde adsorption. The COads species thus react with adsorbed OH to produce CO2 through step 11. Trace amount of CH4 at the potential of <0.4 V has been detected, thus the following reaction may occur [53,54] ... 

Fig. 11 Chronoamperometric Faradaic transients for the adsorption of ethanol (a), acetaldehyde (b) on Pt/C (E-TEK) catalyst at differait, constant potentials between +0.06 and +0.36 V is increased in steps of 50 mV). For adsorption, the electrolyte was switched at / = 0 liom the supporting electrolyte to solutions containing 0.1 M ethanol ot acetaldehyde. The cinrent transients of acetaldehyde adsorption (b) are progressively shifted by 2 s for clarity [34]...

---