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[Display omitted] • The competition adsorption mechanism of NH 3 and CB at low temperature is revealed. • Byproduct of NH 3 -SCO promotes deep oxidation of intermediates in CBCO reaction. • The forms of N and Cl species in simultaneous catalytic oxidation are unveiled. As the emission limits for NO x become further stringent, development of a synergistic control technology to prevent emissions of slipped ammonia (NH 3) and chlorinated organics from steel production and waste incineration is both a prospect and a challenge for the environmental issues. In this work, the designed ruthenium-based catalyst (RuNb/ST) showed the excellent chlorobenzene (CB)/NH 3 synergistic removal performance and N 2 /CO 2 selectivity above 300 ℃. The activity of NH 3 and CB were suppressed at relatively low temperature due to the competitive adsorption of CB and NH 3. Whereas, there was a significant improvement in the N 2 /CO 2 selectivity at relatively high temperature. The removal mechanism was studied by experiments, in which the accumulation of chlorine species, the role of NO 2 and the oxidation of CB were considerable. In contrast to the carrier, the vast majority of the chloride ions adsorbed onto the active sites after dissociating from CB could be efficiently removed in form of Cl 2 via the Deacon Reaction catalyzed by RuO 2. CB was predominantly converted into CO 2 and H 2 O with a fraction persisting as organics. Partial of organics were attacked by Cl ions to generate organic chlorine-containing by-products. The presence of NO 2 molecule was found to promote the cleavage of the benzene ring within CB, and expedited the carbon migration towards the ultimate product of CO 2 , resulting in a notable reduction of byproducts. [ABSTRACT FROM AUTHOR]

Abstract In this study, the cobalt-cerium spinel oxides catalysts were prepared via a citric acid complex method. The catalytic performance and physicochemical properties of the samples for deep propane oxidation were evaluated. Co 2 Ce 1 O x catalysts exhibit the superior low temperature activity with a T 50 value of 220 °C, which is much lower than both individual cobalt and cerium oxides. The results show that cerium ions could enter into the spinel-type lattice of the cobalt oxides and lead to the severe lattice distortion. The activated Co O bonds favor the propane activation and enhance the reducibility of active Co3+ species. Meanwhile, high proportion of Co3+ content and better oxygen mobility are also observed in the cobalt-cerium spinel oxides catalysts. The kinetic and the transient experiments reveal that the reduction step of the catalysts plays a crucial role in the deep catalytic propane oxidation. The reaction rate of Co 2 Ce 1 O x catalyst reaches 0.22 μmol g−1 s−1 at 200 °C and its activation energy is the lowest (57.9 kJ mol−1). All the results indicate that the combination of redox behaviors of Co 3 O 4 and oxygen vacancies of CeO 2 offer useful support for catalysts design toward propane oxidation at low temperature. Graphical abstract Unlabelled Image Highlights • Catalytic propane oxidation was performed over cobalt-cerium spinel oxides catalysts. • Co 2 Ce 1 O x showed the highest low temperature activity. • Reduction step of the catalysts is crucial for catalytic propane oxidation. • Proportion of Co3+ is linear with the reaction rates at 200 °C. [ABSTRACT FROM AUTHOR]

Abstract In recent years, significant effort has been made in the development of novel catalysts for the total oxidation of chlorinated volatile organic compounds. In this work the catalytic activity of Cu doped cerium-titanium binary oxides for the oxidation of dichloromethane (DCM) have been studied for the first time. Combining catalysts characterization and activity data, it was found that Cu ions can uniformly disperse into titanium dioxide to form solid solution and induce the creation of additional surface oxygen species on the catalysts surface, while moderate amount of Ce ions are still needed for the activation of C Cl. Detailed analysis of the in-situ FTIR experiment results revealed that the surface oxygen species, especially the hydroxyl groups associated with Cu ions, can promote the deep oxidation of the intermediate species formed in the nucleophilic substitution process occurred on the active sites of catalysts surface. The sample with the Cu/Ce molar ratio of 1:3 obtained a better CO 2 selectivity than that reached with cerium-titanium binary oxides. Meanwhile, according to element balance analysis, removal of chlorine from the catalyst surface was also promoted by Cu doping. Graphical abstract Image 1 Highlights • Catalytic oxidation of dichloromethane over Ce, Cu, Ti ternary oxides has been studied. • Cu doping can promote the products selectivity to CO2 and enhance Cl balance. • Correlation between catalyst structure and catalytic behavior is revealed. • Promotion Mechanism of Cu doping for dichloromethane deep oxidation was explored. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel catalysts for CVOCs removal present excellent low-temperature activity and high chlorine resistance. • WO x loading affects the surface species morphology while polymer structure at 10% loading shows the best performance. • The RuO 2 -WO x /Sn 0.2 Ti 0.8 O 2 catalysts exhibit highly stable activity in both dry and wet conditions. • Experimental and computational results prove WO 2 Cl 2 to be the main species for tungsten loss on chlorine poisoned catalysts. • The removal performance of CB, TCE and DCM by the cordierite catalyst is validated. The development of catalysts with high activity, selectivity, and durability is crucial for the catalytic oxidation of chlorinated volatile organic compounds (CVOCs). Although acid-modified supports are widely used in catalysis to improve the catalytic activity at low temperature, the acid sites are easily deactivated by Cl poisoning, and the poisoning mechanism remains unclear. Here, a series of RuO 2 -WO x /Sn 0.2 Ti 0.8 O 2 catalysts were synthesized for dichloromethane (DCM) catalytic oxidation. Spectroscopic characterizations revealed that the loading amount of tungsten oxide highly affects the structure of the surface species and, consequently, the low-temperature catalytic activity. SEM, XRD and DFT calculations elucidated that the loss of tungsten species in the form of WO 2 Cl 2 is the main reason for the catalyst deactivation. By loading RuO 2 , the loss of tungsten species could be effectively avoided via the Deacon reaction. The cordierite catalyst exhibits excellent catalytic activity for the oxidation of different types of CVOCs. [ABSTRACT FROM AUTHOR]

In this work, plasma-catalytic oxidation of low concentration ethyl acetate (100 ppm) over La 1-x Ce x CoO 3+δ (x = 0, 0.05, 0.1, 0.3 and 0.5) perovskite catalysts was carried out in a coaxial dielectric barrier discharge (DBD) reactor. The effects of Ce-doping on the removal of ethyl acetate and CO x (x = 1 and 2) selectivity in the plasma-catalytic oxidation process were investigated as a function of specific energy density (SED). Compared to the plasma reaction without a catalyst, the presence of the LaCoO 3 catalyst in the plasma enhanced the removal of ethyl acetate and CO x selectivity. The use of the Ce-doped catalysts further enhanced the performance of the plasma-catalytic oxidation process. The highest removal efficiency of ethyl acetate (100%) and CO x selectivity (91.8%) were achieved in the plasma-catalytic oxidation of ethyl acetate over the La 0.9 Ce 0.1 CoO 3+δ catalyst at a SED of 558 J L −1 . The interactions between Ce and LaCoO 3 resulted in an increased specific surface area (by 17.1%–68.6%) and a reduced crystallite size (by 13.5%–68.2%) of the Ce-doped LaCoO 3 catalysts compared to pure LaCoO 3 , which favours the oxidation of ethyl acetate in the plasma process. Compared to the LaCoO 3 catalyst, the Ce-doped perovskite catalysts showed higher content (maximum 54.9%) of surface adsorbed oxygen (O ads ) and better reducibility, both of which significantly contributed to the enhanced oxidation of ethyl acetate and intermediates in the plasma-assisted surface reactions. The coupling of plasma with the Ce-doped catalysts also reduced the formation of by-products including NO 2 and N 2 O. The possible reaction pathways involved in the plasma oxidation process have been discussed. [ABSTRACT FROM AUTHOR]

Plasma-catalytic removal of low concentration ethyl acetate was carried out over La 0.8 M 0.2 MnO 3 (M = Ba, Ca, Ce, Mg and Sr) catalysts prepared by sol-gel method using citric acid as a mixing complex. The La 0.8 Ce 0.2 MnO 3 catalyst showed the highest removal of ethyl acetate and CO 2 selectivity over the specific energy density (SED) range followed by the La 0.8 Sr 0.2 MnO 3 catalyst, while Ba, Ca and Mg-doped catalysts inhibited the oxidation of ethyl acetate compared to the pure LaMnO 3 catalyst. A wide range of catalyst characterization including N 2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction by H 2 (H 2 -TPR) indicated that the reducibility of the catalysts played an important role in determining the reaction performance of the plasma-catalytic gas cleaning process. [ABSTRACT FROM AUTHOR]

This paper investigated the enhancement of plasma on dimethyl sulfide (DMS) removal over commercial V-W/Ti catalysts. The effects of catalyst composition, discharge power, and gas temperature on DMS removal in the plasma-based system were analyzed. The results showed that the V0.9–W/Ti catalyst exhibited the best performance toward DMS removal due to its highest reducibility among the employed samples. The introduction of plasma exhibited a synergistic effect on catalysts and significantly enhanced the removal of DMS over the studied temperature range, especially in high discharge power cases. The activation energy Ea of DMS removal in the presence of plasma was dramatically reduced to less than 10% of the catalysis only case, indicating different DMS removal pathways in plasma-activated catalysis system. The reaction mechanisms of DMS were also discussed based on the reaction products. [ABSTRACT FROM PUBLISHER]

TiO 2 –carbon and vanadium–TiO 2 –carbon composite nanofibrous membranes were synthesized through electrospinning and investigated for the complete oxidation of low-concentration acetone. The novel nanofibrous membranes were characterized through various techniques, including TG/DSC, SEM-EDX, HRTEM, XRD, N 2 sorption, XPS, NH 3 -TPD, and H 2 -TPR analyses. Introduction of vanadium at an appropriate amount enhances the catalytic performance in complete acetone oxidation. The best result was obtained with 10V–TiC nanofibers that contain 10 wt.% vanadium. Furthermore, the 10V–TiC nanofibers displayed higher activity than that of the V 2 O 5 /TiO 2 reference catalyst prepared by impregnation method. Characterization results indicate that these fibers exhibit a typical nanofibrous morphology. Vanadium incorporation accelerates the decomposition of the gel precursor nanofibers and causes variations in textural properties, surface chemistry, acidity, and reducibility. The high porosity of the nanofibrous structure, abundant adsorbed oxygen species on the surface, strong acidity, and reducibility enhance the catalytic performance. [ABSTRACT FROM AUTHOR]

• Developed a new RuO 2 -WO 3 /Sn 0.2 Ti 0.8 O 2 catalyst formula for CVOCs catalytic removal. • Studied the effect of RuO 2 loading on catalyst's acidity and catalytic performance. • Studied the synergistic catalysis of CVOCs and multiple pollutant components. Chlorine-containing volatile organic compounds emitted from combustion boilers and chemical industries will cause great harm to the ecological environment and human health. Catalytic combustion technology is one of the commonly used technologies for the treatment of CVOCs. Poor low-temperature activity, high levels of toxic by-products, and poor resistance to chlorine poisoning are common problems faced by its catalyst development. In order to effectively remove CVOCs, we constructed a RuO 2 -WO 3 / Sn 0.2 Ti 0.8 O 2 catalyst formula in which RuO 2 and WO 3 were supported on Sn 0.2 Ti 0.8 O 2 , and tested with DCM as a model molecule. By detecting the catalytic performance of RuO 2 -WO 3 /Sn 0.2 Ti 0.8 O 2 series catalysts with different RuO 2 loadings on DCM and corresponding characterization methods, we found that 3 wt%RuO 2 -5 wt%WO 3 /Sn 0.2 Ti 0.8 O 2 catalyst had the best catalytic performance (T 90% value was 291 °C, CO 2 selectivity was close to 100% at 325 °C). The actual industrial environment often contains multiple gas pollutants at the same time, so it is important to study the ability of the catalyst to co-process multiple pollutants. The effects of other pollutants (propane, acetone, SO 2 and NO 2) in the reaction atmosphere on the catalytic oxidation performance of DCM were further studied. It was found that the RuO 2 -WO 3 /Sn 0.2 Ti 0.8 O 2 catalyst could achieve the coordinated removal of acetone, propane and dichloromethane, and the effects of SO 2 and NO 2 on catalytic oxidation performance of DCM was revealed. It is hoped that it can serve as a reference and guidance for the subsequent industrial application of the catalyst in this system. [ABSTRACT FROM AUTHOR]

• DFT found defective sites on δ-MnO 2 displayed higher Hg0 removal potential. • Mo-adjusted δ-MnO 2 nanosheet achieved excellent Hg0 removal efficiency. • 1.25Mo2 Mn exhibited superior catalytic oxidation of Hg0 to Hg2+ performance. • Mo showed promotional defective and dispersive effect of δ-MnO 2 nanosheet. • Synergistic interactions between the MnO 2 nanosheet and MoO 3 were adjusted. The challenge of Hg0 emission control has necessitated the development of catalytic oxidation technology. Herein, a combination of experimental and computational approach to explore the potential over Mo-Mn catalysts was conducted. Series of catalysts were synthesized and characterized with varying Mn and Mo loading (1–10%). Among the various compositions, 1.25Mo2 Mn catalyst exhibited the best Hg0 removal performance with Hg0 removal efficiency > 98% (oxidation ratio > 50%, and better stability over 10 h period at 250 °C). Most importantly, the synergistic interaction between MoO 3 and defective δ-MnO 2 nanosheet was promoted by the adjusted activation energy, bond strength, Brønsted acidic sites and defects, which facilitated the catalytic oxidation of Hg0 to Hg2+. Furthermore, DFT calculations suggested that the role of Mo enabled the reduction in the energy barrier for the desorption step, which was defined as the rate-determining step for catalytic oxidation of Hg0 on Mn-based catalyst. [ABSTRACT FROM AUTHOR]

• Catalytic oxidation of Hg0 by O2 on MoO3-CeO2 catalyst was studied. • MoO3 results in the explosion of additional CeO2 (111) surface. • CeO2 and MoO3 show synergistic effect on formation of Brønsted acid sites. • Synergistic coupling between CeO2 and MoO3 boost the catalytic oxidation. Based on Volcano plotting, the controlled combination of weak and strong bond strengths of a bimetallic catalyst has the potential to maximize the catalytic effect via the formation of intermediate bond strength between the reactant and the two different types of active sites. In this study, a rational design approach was adopted to couple MoO 3 and CeO 2 to maximize the catalytic oxidation of Hg0 using oxygen as the oxidizing agent. It is found that CeO 2 displayed a relatively strong bond strength with Hg0 while MoO 3 has relatively weak bond strength with Hg0; the pre-doping of MoO 3 results in the transformation of CeO 2 from clusters to the form with additional exposed CeO 2 (111) surface; the CeO 2 and MoO 3 show synergistic effect on the formation of Brønsted acid sites. Moreover, the results show that there is an overlap between the Hg0 desorption region of MoO 3 and the Hg0 adsorption region of CeO 2 (with adjusted optimum bond strength with Hg0), which contributes to the catalytic reaction of Hg0 by O 2. Therefore, this study reveals that the synergistic effects of the coupling of CeO 2 and MoO 3 induced the reaction between Hg0 and O 2 , which is otherwise difficult. [ABSTRACT FROM AUTHOR]