Room-temperature catalytic oxidation of formaldehyde on catalysts

2016 ◽  
Vol 6 (11) ◽  
pp. 3649-3669 ◽  
Author(s):  
Longhui Nie ◽  
Jiaguo Yu ◽  
Mietek Jaroniec ◽  
Franklin Feng Tao
Keyword(s):  
Catalytic Oxidation ◽  
Indoor Air ◽  
Room Temperature ◽  
Oxidative Decomposition

Room-temperature catalytic oxidative decomposition of harmful formaldehyde (HCHO) in indoor air is summarized.

scholarly journals Non-Destructive Detection of Pentachlorophenol Residues in Historical Wooden Objects

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1052
Author(s):  
Ida Kraševec ◽  
Nataša Nemeček ◽  
Maja Lozar Štamcar ◽  
Irena Kralj Cigić ◽  
Helena Prosen
Keyword(s):  
Indoor Air ◽  
Room Temperature ◽  
Quantitative Methods ◽  
Solid Phase ◽  
Contact Mode ◽  
Solvent Extraction Method ◽  
Museum Objects ◽  
Wooden Furniture ◽  
Non Destructive ◽  
Heritage Collections

Wood is a natural polymeric material that is an important constituent of many heritage collections. Because of its susceptibility to biodegradation, it is often chemically treated with substances that can be harmful to human health. One of the most widely used wood preservatives was pentachlorophenol (PCP), which is still present in museum objects today, although its use has been restricted for about forty years. The development of non-destructive methods for its determination, suitable for the analysis of valuable objects, is therefore of great importance. In this work, two non-destructive solid-phase microextraction (SPME) methods were developed and optimized, using either headspace or contact mode. They were compared with a destructive solvent extraction method and found to be suitable for quantification in the range of 7.5 to 75 mg PCP/kg wood at room temperature. The developed semi-quantitative methods were applied in the wooden furniture depot of National Museum of Slovenia. PCP was detected inside two furniture objects using headspace mode. The pesticide lindane was also detected in one object. The indoor air of the depot with furniture was also sampled with HS SPME, and traces of PCP were found. According to the results, SPME methods are suitable for the detection of PCP residues in museum objects and in the environment.

scholarly journals Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Shiqiang Zhou ◽  
Mingpeng Chen ◽  
Qingjie Lu ◽  
Yumin Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Indoor Air ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Unsolved Problem ◽  
Air Pollutant ◽  
Ag Nps ◽  
Performance Targets ◽  
Fabrication Cost ◽  
Low Concentrations ◽  
Stringent Performance

AbstractFormaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

Influence of alkali metals on Pd/TiO2 catalysts for catalytic oxidation of formaldehyde at room temperature

2016 ◽  
Vol 6 (7) ◽  
pp. 2289-2295 ◽  
Author(s):  
Yaobin Li ◽  
Changbin Zhang ◽  
Hong He ◽  
Jianghao Zhang ◽  
Min Chen
Keyword(s):  
Catalytic Oxidation ◽  
Alkali Metals ◽  
Room Temperature ◽  
Promotion Effect

We previously observed that sodium (Na) addition had a dramatic promotion effect on Pd/TiO2 catalysts for formaldehyde (HCHO) oxidation.

scholarly journals Study on energy loss and thermal environment through door open while air conditioner running

2019 ◽  
Vol 111 ◽  
pp. 06035
Author(s):  
Sihwan Lee
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Room Temperature ◽  
Thermal Environment ◽  
Infiltration Rate ◽  
Operating Efficiency ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Cooling Period ◽  
Closed State

While air conditioner is running, opening doors and windows is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy consumption of air conditioners with door opened and door closed state were measured. The measured results show that the infiltration rate at the door opened state was increased by about 21.3 times compared to the door closed state. When the set temperature of the air conditioner was 24 °C, the room temperature in the opening gate cooling was measured to be about 5 °C higher than the closing gate cooling. However, the energy consumption was measured approximately 12 kWh/day and there was no difference with door state. This means that the energy consumption is not increased if the indoor air temperature would not reach the set point temperature of air conditioner.

scholarly journals A single iron site confined in a graphene matrix for the catalytic oxidation of benzene at room temperature

2015 ◽  
Vol 1 (11) ◽  
pp. e1500462 ◽  
Author(s):  
Dehui Deng ◽  
Xiaoqi Chen ◽  
Liang Yu ◽  
Xing Wu ◽  
Qingfei Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Catalytic Oxidation ◽  
Room Temperature ◽  
Single Atom ◽  
Intermediate Structure ◽  
Oxidation Reactions ◽  
Transmission Electron ◽  
Oxidation Of Benzene

Coordinatively unsaturated (CUS) iron sites are highly active in catalytic oxidation reactions; however, maintaining the CUS structure of iron during heterogeneous catalytic reactions is a great challenge. Here, we report a strategy to stabilize single-atom CUS iron sites by embedding highly dispersed FeN4 centers in the graphene matrix. The atomic structure of FeN4 centers in graphene was revealed for the first time by combining high-resolution transmission electron microscopy/high-angle annular dark-field scanning transmission electron microscopy with low-temperature scanning tunneling microscopy. These confined single-atom iron sites exhibit high performance in the direct catalytic oxidation of benzene to phenol at room temperature, with a conversion of 23.4% and a yield of 18.7%, and can even proceed efficiently at 0°C with a phenol yield of 8.3% after 24 hours. Both experimental measurements and density functional theory calculations indicate that the formation of the Fe═O intermediate structure is a key step to promoting the conversion of benzene to phenol. These findings could pave the way toward highly efficient nonprecious catalysts for low-temperature oxidation reactions in heterogeneous catalysis and electrocatalysis.

Dual-dehydrogenation-promoted catalytic oxidation of formaldehyde on alkali-treated Pt clusters at room temperature

2015 ◽  
Vol 3 (19) ◽  
pp. 10432-10438 ◽  
Author(s):  
Peng Zhou ◽  
Jiaguo Yu ◽  
Longhui Nie ◽  
Mietek Jaroniec
Keyword(s):  
Catalytic Oxidation ◽  
Room Temperature ◽  
Pt Catalysts

Dual dehydrogenation of HCHO molecules can promote the activation of O2 molecules and regeneration of Pt catalysts.

Surface oxygen vacancies on Co3O4 mediated catalytic formaldehyde oxidation at room temperature

2016 ◽  
Vol 6 (11) ◽  
pp. 3845-3853 ◽  
Author(s):  
Zhong Wang ◽  
Wenzhong Wang ◽  
Ling Zhang ◽  
Dong Jiang
Keyword(s):  
Catalytic Oxidation ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Essential Role ◽  
Surface Oxygen ◽  
Oxidation Reactions ◽  
Major Activity ◽  
Formaldehyde Oxidation ◽  
The Common

This study reveals the essential role played by surface oxygen vacancies in catalytic oxidation reactions, and complements the common viewpoint that Co3+ is the major activity species in Co3O4-based systems.

Flexible nickel foam decorated with Pt/NiO nanoflakes with oxygen vacancies for enhanced catalytic formaldehyde oxidation at room temperature

2017 ◽  
Vol 4 (11) ◽  
pp. 2215-2224 ◽  
Author(s):  
Shuying Huang ◽  
Xiaofeng Zhu ◽  
Bei Cheng ◽  
Jiaguo Yu ◽  
Chuanjia Jiang
Keyword(s):  
Ambient Temperature ◽  
Catalytic Oxidation ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Nickel Foam ◽  
Formaldehyde Oxidation

Flexible nickel foam coated with Pt/NiO nanoflakes was prepared for HCHO catalytic oxidation at ambient temperature.

Developing a Healthy, Comfortable and Energy-Saving Office Building

2012 ◽  
Vol 193-194 ◽  
pp. 45-50 ◽  
Author(s):  
Wen Pei Sung ◽  
Yi Rou Chi ◽  
Lin Jun Hong ◽  
Yu Kuang Zhao
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Room Temperature ◽  
Office Building ◽  
Tropical Region ◽  
High Humidity ◽  
Indoor Temperature ◽  
Office Environment ◽  
Research Show

How to maintain a comfortable indoor environment without excessively relying on mechanical HVAC (Heating, Ventilation, and Air Conditioning) is a target to be pursued for future living requirements. The results obtained in this research show that in an office environment, the room temperature monitored during winter is close to the comfortable temperature; however, the office occupants feel that a little warmer indoor temperature is comfort. During summer, the occupants prefer cooler temperature than the comfort temperature. Additionally, Taiwan is located in sub-tropical region with hot and humid summer. Even if the room temperature is maintained in a comfortable range, the occupants still feel not so comfortable because of high humidity. Hence, reducing the room temperature below 23 °C is inferred to make occupants feel comfortable. Questionnaire survey indicates that ventilation is preferred by 30.9% of the respondents for summer and 43.3% for winter as an effective method to improve the stuffy indoor air.

Photocatalytic Degradation of Gaseous Formaldehyde by Modified Hierarchical TiO2 Nanotubes at Room Temperature

2016 ◽  
Vol 69 (3) ◽  
pp. 343 ◽  
Author(s):  
Di Gu ◽  
Baohui Wang ◽  
Yanji Zhu ◽  
Hongjun Wu
Keyword(s):  
Indoor Air ◽  
Room Temperature ◽  
Air Pollutant ◽  
Noble Metal Nanoparticles ◽  
Reaction Rate Constants ◽  
Volatile Organic ◽  
Major Process ◽  
Formaldehyde Degradation ◽  
Tio2 Nts ◽  
Gaseous Formaldehyde

As a major indoor air pollutant, formaldehyde released from building and furnishing materials is one of the main volatile organic compounds (VOCs). Hierarchical TiO2 nanotube arrays (TiO2 NTs) prepared via a facile two-step anodization showed excellent photocatalytic (PC) degradation of formaldehyde at room temperature. Modification with noble metal nanoparticles (NMNs) could further improve the PC activity of TiO2 NTs. The final products of formaldehyde degradation were detected to be CO2 and H2O, which indicated that the mineralization of formaldehyde was the major process in this PC reaction. The reaction rate constants (k) determined for the three catalysts were in the order kTiO2 NTs < kAu/TiO2 NTs < kPt/TiO2 NTs (Pt/TiO2 NTs had the highest PC ability). The significant enhancement of PC performance can be ascribed to the formation of a Schottky junction between the NMNs and TiO2 NTs.

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