scholarly journals Effect of textual features and surface properties of activated carbon on the production of hydrogen peroxide from hydroxylamine oxidation

RSC Advances ◽  
2017 ◽  
Vol 7 (41) ◽  
pp. 25305-25313 ◽  
Author(s):  
Wei Song ◽  
Lin Yu ◽  
Xiaowei Xie ◽  
Zhifeng Hao ◽  
Ming Sun ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Liquid Phase ◽  
Gas Phase ◽  
Surface Properties ◽  
Textural Features ◽  
Production Of Hydrogen ◽  
Textual Features

Herein, the textural features and surface properties of activated carbon were mediated by oxidation in the gas-phase or liquid-phase.

scholarly journals Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 674 ◽  
Author(s):  
Haodong Tang ◽  
Bin Xu ◽  
Meng Xiang ◽  
Xinxin Chen ◽  
Yao Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Liquid Phase ◽  
Gas Phase ◽  
Nitrogen Doping ◽  
Catalyst Surface ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Pd Catalyst ◽  
Nitrogen Doped ◽  
The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

Hybrid Gas/Liquid Electrical Discharge Reactors with Zeolites for Colored Wastewater Degradation

2005 ◽  
Vol 8 (2) ◽  
Author(s):  
Hrvoje Kušić ◽  
Natalija Koprivanac ◽  
Igor Peternel ◽  
Bruce R. Locke
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Electrical Discharge ◽  
Organic Dye ◽  
Electrical Discharges ◽  
Colored Wastewater ◽  
Ozone Levels ◽  
Parallel Reactor

AbstractHybrid gas/liquid electrical discharge reactors have been used to degrade an organic dye in the presence and absence of zeolites. Simultaneous gas and liquid phase electrical discharges in the hybrid parallel and hybrid series reactors have been shown in previous work to lead to the formation of hydrogen peroxide and hydroxyl radicals in the liquid phase and ozone in the gas phase. These reactors differ in their electrode configuration, and in previous work it was shown that the ozone levels in the parallel reactor are seven times higher than in the series reactor (3000 ppm and 450 ppm, respectively), while both reactors produce the same levels of hydrogen peroxide (4.9 × 10

scholarly journals Partitioning of hydrogen peroxide in gas-liquid and gas-aerosol phases

2020 ◽  
Author(s):  
Xiaoning Xuan ◽  
Zhongming Chen ◽  
Yiwei Gong ◽  
Hengqing Shen ◽  
Shiyi Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Pure Water ◽  
Average Concentration ◽  
Effective Field ◽  
Urban Atmosphere ◽  
Ambient Atmosphere ◽  
Henry's Law ◽  
Henry’S Law

Abstract. Hydrogen peroxide (H2O2) is a vital oxidant in the atmosphere and plays critical roles in the oxidation chemistry of both liquid and aerosol phases. The partitioning of H2O2 between the gas and liquid phase or the aerosol phase could affect its abundance in these condensed phases and eventually the formation of secondary components. However, the partitioning processes of H2O2 in gas-liquid and gas-aerosol phases are still unclear, especially in the ambient atmosphere. In this study, field observations of gas-, liquid-, and aerosol-phase H2O2 were carried out in the urban atmosphere of Beijing during the summer and winter of 2018. The effective field-derived mean value of Henry's law constant (HAm, 2.1 × 105 M atm−1) was 2.5 times that of the theoretical value in pure water (HAt, 8.4 × 104 M atm−1) at 298 ± 2 K. The effective derived gas-aerosol partitioning coefficient (KPm, 3.8 × 10−3 m3 μg−1) was four orders of magnitude higher on average than the theoretical value (KPt, 2.8 × 10−7 M atm−1) at 270 ± 4 K. The partitioning of H2O2 in the gas-liquid and gas-aerosol phases in the ambient atmosphere does not only obey Henry's law or Pankow's absorptive partitioning theory but is also influenced by certain physical and chemical reactions. The average concentration of liquid-phase H2O2 in rainwater during summer was 44.12 ± 26.49 μM. In three-quarters of the collected rain samples, the measured H2O2 was greater than the predicted value in pure water calculated by Henry's law. In these samples, 46 % of the measured H2O2 was from gas-phase partitioning, and most of the rest may have come from residual H2O2 in raindrops. In winter, the level of aerosol-phase H2O2 was 0.093 ± 0.085 ng μg−1, which was much higher than the predicted value based on Pankow's absorptive partitioning theory. Almost all aerosol-phase H2O2 was not from the partitioning of the gas phase. The decomposition/hydrolysis of aerosol-phase organic peroxides could be responsible for 32 % of aerosol-phase H2O2 formation at the maximum rate of 3.65 ng μg−1. Furthermore, the heterogeneous uptake of H2O2 on aerosols contributed to less than 0.5 %.

Ramie Biomass Derived Nitrogen-Doped Activated Carbon for Efficient Electrocatalytic Production of Hydrogen Peroxide

2018 ◽  
Vol 165 (5) ◽  
pp. E171-E176 ◽  
Author(s):  
Yudong Xue ◽  
Xuan Du ◽  
Weiquan Cai ◽  
Zhi Sun ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Nitrogen Doped ◽  
Production Of Hydrogen

scholarly journals Enhanced Catalytic Hydrogen Peroxide Production from Hydroxylamine Oxidation on Modified Activated Carbon Fibers: The Role of Surface Chemistry

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1515
Author(s):  
Wei Song ◽  
Ran Zhao ◽  
Lin Yu ◽  
Xiaowei Xie ◽  
Ming Sun ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Reaction Pathway ◽  
Volume Ratio ◽  
Activated Carbon Fiber ◽  
H2o2 Production ◽  
Direct Production ◽  
Modified Activated Carbon ◽  
Production Of Hydrogen

Herein, direct production of hydrogen peroxide (H2O2) through hydroxylamine (NH2OH) oxidation by molecular oxygen was greatly enhanced over modified activated carbon fiber (ACF) catalysts. We revealed that the higher content of pyrrolic/pyridone nitrogen (N5) and carboxyl-anhydride oxygen could effectively promote the higher selectivity and yield of H2O2. By changing the volume ratio of the concentrated H2SO4 and HNO3, the content of N5 and surface oxygen containing groups on ACF were selectively tuned. The ACF catalyst with the highest N5 content and abundant carboxyl-anhydride oxygen containing groups was demonstrated to have the highest activity toward catalytic H2O2 production, enabling the selectivity of H2O2 over 99.3% and the concentration of H2O2 reaching 123 mmol/L. The crucial effects of nitrogen species were expounded by the correlation of the selectivity of H2O2 with the content of N5 from X-ray photoelectron spectroscopy (XPS). The possible reaction pathway over ACF catalysts promoted by N5 was also shown.

scholarly journals Accessibility enhancement of TS-1-based catalysts for improving the epoxidation of plant oil-derived substrates

2016 ◽  
Vol 6 (19) ◽  
pp. 7280-7288 ◽  
Author(s):  
Nicole Wilde ◽  
Jan Přech ◽  
Marika Pelz ◽  
Martin Kubů ◽  
Jiří Čejka ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Methyl Oleate ◽  
Model Compound ◽  
Textural Features ◽  
Plant Oil ◽  
Liquid Phase Epoxidation

TS-1-based catalysts with different textural features, namely layered TS-1, pillared TS-1, and Ti-pillared TS-1 as well as mesoporous TS-1, were investigated in the liquid-phase epoxidation of methyl oleate as a model compound for plant oil-derived substrates with hydrogen peroxide at 50 °C.

scholarly journals Gas phase stabiliser-free production of hydrogen peroxide using supported gold–palladium catalysts

2016 ◽  
Vol 7 (9) ◽  
pp. 5833-5837 ◽  
Author(s):  
Adeeba Akram ◽  
Simon J. Freakley ◽  
Christian Reece ◽  
Marco Piccinini ◽  
Greg Shaw ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Gas Phase ◽  
Palladium Catalysts ◽  
Pd Catalysts ◽  
Production Of Hydrogen ◽  
Gold Palladium Catalysts ◽  
Supported Gold

Gas phase hydrogen peroxide is postulated to be a key intermediate in many gas phase oxidations. Using Au–Pd catalysts we show it is possible to synthesise H2O2 in the gas phase from H2 and O2.

Effect of Flow Mode of Gas-Liquid Phase in Graphite-Felt Cathode on Electrochemical Production of Hydrogen Peroxide.

2001 ◽  
Vol 34 (7) ◽  
pp. 884-891 ◽  
Author(s):  
MASAO SUDOH ◽  
MASASHI YAMAMOTO ◽  
TETSURO KAWAMOTO ◽  
KEIICHI OKAJIMA ◽  
NOBUO YAMADA
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Phase ◽  
Flow Mode ◽  
Graphite Felt ◽  
Production Of Hydrogen ◽  
Electrochemical Production
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