Carboxyl groups trigger the activity of carbon nanotube catalysts for the oxygen reduction reaction and agar conversion

Highly Porous Nitrogen- and Phosphorus-Codoped Graphene: An Outstanding Support for Pd Catalysts to Oxidize 5-Hydroxymethylfurfural into 2,5-Furandicarboxylic Acid

“…7 The carbon-supported Pd catalysts were prepared by formaldehyde reduction of palladium chloride in alkaline aqueous solution. One g of carbon materials (HPGS and reduced graphene oxide (rGO) supplied by Fan's group, 10 carbon nanotubes (CNTs) supplied by Shandong Dazhan Nanomaterials Co., Ltd., China, 11 and purified by HCl washing) dispersed in 10 mL of deionized (DI) water. Then, palladium chloride was added to this suspension (pH > 8 by NaOH adjusting), and it was reduced by formaldehyde at 50 °C for 1 h. The final Pd/HPGS, Pd/rGO, and Pd/ CNT were obtained after a series of filtration, washing, and drying operations, while Pd catalysts supported on activated carbon (AC) was purchased from Hangzhou Canan New Material Co. Ltd., China.…”

Trihalomethane, dihaloacetonitrile, and total N-nitrosamine precursor adsorption by carbon nanotubes: the importance of surface oxides and pore volume

“…44 It has also been shown that the presence of surface oxides increases the hydrophilicity of CNT surfaces, which could enhance the adsorption of hydrophilic DBP precursors, such as those that react with chloramines to form N-nitrosamines. 48 Additionally, aminebased groups serving as N-nitrosamine precursors are positively charged at circumneutral pH. Thus, these groups would experience electrostatic attractions to the negatively charged carboxylic acid functionalities on the CNTs, which may explain the high removal of TONO precursors relative to TTHM and DHAN precursors.…”

Carbon nanotubes and catalysis: the many facets of a successful marriage

“…In a recent study, each oxygenated functional group (including COOH, OH, and lactones) formed after ozone treatment was correlated with the activity towards ORR and agar conversion, and it was demonstrated that carboxylic acid moieties are actually the essential functional groups for these two catalytic reactions. 35 Similarly, carboxylic acid groups were found to be responsible for the high activity of o-MWCNTs towards the wet air oxidation of phenol, which was completely removed after only 1 hour of reaction time. 36 Oxidation is not the sole available technique to modify CNTs.…”

“…In a recent study, each oxygenated functional group (including COOH, OH, lactones) formed after ozone treatment was correlated with the activity towards ORR and agar conversion, and it was demonstrated that carboxylic acid moieties are actually the essential functional groups for these two catalytic reactions. 35 Similarly, carboxylic acid groups were found to be responsible for the high activity of o-Oxidation is not the sole available technique to modify CNTs. In reality, research on organic covalent functionalization has much progressed in the last ten years and as of today it is possible to design CNTs bearing specific functional groups that exhibit well-defined catalytic behaviors.…”