Study on mesoporous catalysts for oxidation of volatile organic compounds

Volatile organic compounds (VOCs) emitted from many industrial processes, are harmful to human health and the atmsphere. Several technologies are currently used to eliminate VOCs from the environment. Among them, catalytic oxidation has been recognized as one of the most efficient and promising ways to treatment VOCs. So high performance oxidants play an dominant role in the catalytic oxidation process. In this work, we discussed many researchers’ works about preparation and effect of their catalysts, kinds of mesoporous catalysts for eliminating VOCs were reviewed, the active components of the catalysts are noble and non-noble metal oxides, which loaded in the mesochannels of mesoporous materials including silica, titania and aluminia.

Nanocarved Vanadium Nitride Nanowires Encapsulated in Lamellar Graphene Layers as Supercapacitor Electrodes

Supercapacitors have the characteristics of high specific capacitance, long cycle life and fast charging ability, which have shown extremely valuable applications in energy storage fields. Improving the electrode materials is a crucial approach to achieve high capacity. Vanadium nitride (VN) has higher theoretical capacitance than noble metal oxides, as well as better chemical stability and good electrical conductivity. Herein, a composite of VN nanowires with multiple cavities encapsulated in N-doped reduced graphene oxide lamellar layers (VNNWs@rGO) has been synthesized by facile freeze-casting and subsequent nitridation technique. The hierarchical VNNWs@rGO composite exhibited excellent supercapacitor performance: high capacitances of 222 and 65 F g− 1 were achieved at current densities of 0.5 and 10 A g− 1, respectively. The improved electrochemical performance is associated with the unique structural design: the N-doped rGO sheets endowed enhanced electric conductivity and chemical stability for VN, the interconnected laminar network of VNNWs@rGO are crucial for electrolyte penetration and charge transfer, and the cavities and nanoparticles inside the VN nanowires can provide abundant active sites for electric double layer capacitor and pseudocapacitance.

P-type Cobaltite Oxide Spinel Enables Efficient Electrocatalytic Oxygen Evolution Reaction

Energy-efficient electrocatalytic oxygen evolution from water requires today the usage of noble metal oxides. Here we show that highly p-conducting zinc cobaltite spinel Zn1.2Co1.8O3.5 offers an enhanced electrocatalytic activity for...

TiO2 Surface Hybridisation with Noble Metals (Ag and CuxO) for Solar De-NOx and VOC Removal

<p>Indoor and outdoor air pollution remains a major health risk for human beings. Nitrogen oxides and volatile organic compounds are amongst the major pollutant found outdoor. Thus, actions to diminish such risks and to provide safer outdoor / indoor environment are required. In this research work, we have decorated the surface of TiO₂ with noble-metal oxides (Ag and/or Cu<i>_x</i>O) to improve the photocatalytic performances (removal of nitrogen oxides and benzene) under simulated solar-light irradiation. By means of advanced X-ray methods it has been shown that noble metals did not enter the TiO₂ crystal structure, although they retarded the anatase-to-rutile phase transition and crystal growth. </p> <p>Photocatalytic activity was assessed in the gas-solid phase, monitoring the degradation of NO<i>_x</i> and benzene, using a lamp simulating the solar radiation. Results showed that TiO₂ modified with an Ag:Cu molar ratio equal to 1:1 (with Ag+Cu = 0.5+0.5 mol% = 1 mol%), was that exhibiting best de-NO<i>_x</i> and benzene removal performances.</p>

TiO2 Surface Hybridisation with Noble Metals (Ag and CuxO) for Solar De-NOx and VOC Removal

<p>Indoor and outdoor air pollution remains a major health risk for human beings. Nitrogen oxides and volatile organic compounds are amongst the major pollutant found outdoor. Thus, actions to diminish such risks and to provide safer outdoor / indoor environment are required. In this research work, we have decorated the surface of TiO₂ with noble-metal oxides (Ag and/or Cu<i>_x</i>O) to improve the photocatalytic performances (removal of nitrogen oxides and benzene) under simulated solar-light irradiation. By means of advanced X-ray methods it has been shown that noble metals did not enter the TiO₂ crystal structure, although they retarded the anatase-to-rutile phase transition and crystal growth. </p> <p>Photocatalytic activity was assessed in the gas-solid phase, monitoring the degradation of NO<i>_x</i> and benzene, using a lamp simulating the solar radiation. Results showed that TiO₂ modified with an Ag:Cu molar ratio equal to 1:1 (with Ag+Cu = 0.5+0.5 mol% = 1 mol%), was that exhibiting best de-NO<i>_x</i> and benzene removal performances.</p>

Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers

In order to adopt water electrolyzers as a main hydrogen production system, it is critical to develop inexpensive and earth-abundant catalysts. Currently, both half-reactions in water splitting depend heavily on noble metal catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. The efforts within this field for the discovery of efficient and stable earth-abundant catalysts (EACs) have increased exponentially the last few years. The development of EACs for the oxygen evolution reaction (OER) in acidic media is particularly important, as the only stable and efficient catalysts until now are noble-metal oxides, such as IrOx and RuOx. On the hydrogen evolution reaction (HER) side, there is significant progress on EACs under acidic conditions, but there are very few reports of these EACs employed in full PEM WE cells. These two main issues are reviewed, and we conclude with prospects for innovation in EACs for the OER in acidic environments, as well as with a critical assessment of the few full PEM WE cells assembled with EACs.

Encapsulation of ultrafine metal-oxide nanoparticles within mesopores for biomass-derived catalytic applications

A versatile strategy using MOFs as precursors to encapsulate ultrasmall non-noble metal-oxides nanoparticles in the mesopores of KIT-6 is developed.

Enhancement of Life Time of the Dimensionally Stable Anode for Copper Electroplating Applications

In order to enhance the long-term stability of DSA for copper electroplating process, in the present study, noble metal oxides with excellent electrochemical properties was used and optimum condition was determined the ratio of noble metal oxides, surface pre-treatment of titanium substrate and heat treatment. The effect of the surface pretreatment of titanium substrate and ratio of noble metal oxides were estimated by accelerated test at the highly current density conditions. The lifetime of DSA increase six-fold higher as the oxide thickness of Ta 7 : Ir 3 composition ratio. Under the optimal condition, surface pretreatment led to dramatic increase in the lifetime of DSA.