Zhiping Ye

Bio: Zhiping Ye is an academic researcher from Zhejiang University of Technology. The author has contributed to research in topics: Catalysis & Chemistry. The author has an hindex of 7, co-authored 18 publications receiving 316 citations. Previous affiliations of Zhiping Ye include Ghent University & university of lille.

Influence of the preparation method on the activity of copper-manganese oxides for toluene total oxidation

Abstract: Copper manganese oxides were prepared either by a co-precipitation method using metal nitrates as precursors, tetramethylammonium hydroxide (TMAH) as precipitant or by a redox-precipitation method using manganese acetate and copper nitrate as precursors, permanganate of potassium as oxidant. Copper manganese oxides synthesized by the redox method and calcined at 300 °C were also doped with Pt and Pd (0.5 wt%). The materials were characterized by ICP-OES, X-ray powder diffraction, N2 adsorption/desorption analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy and time-of-flight secondary-ion mass spectrometry. The catalyst properties were assessed in total oxidation of toluene and compared with those of the corresponding single oxides and of a commercial Hopcalite catalyst. Copper manganese oxides were proved to be more active than the single oxides whatever the method of preparation used. CuMnOx prepared via redox method were more active than the catalyst prepared by co-precipitation and compared favorably with the commercial Hopcalite. The overall characterization results revealed that the redox method can ensure a good dispersion of copper in close interaction with manganese preserving more active sites at the outermost layers of the catalyst in comparison with the catalyst obtained via co-precipitation. However all the catalysts deactivate to some extent at the earlier stages of the reaction before to reach a steady-state. For redox catalysts calcined at 300 °C, although the dispersion of trace amount of noble metals does not ensure a better activity, adding Pt allows to get a better resistance to deactivation. Additionally it is to be noticeable that the catalyst using redox-precipitation method calcined at 200 °C outperforms the commercial hopcalite overtime on stream.

The Design of MnOx Based Catalyst in Post-Plasma Catalysis Configuration for Toluene Abatement

Abstract: This review provides an overview of our present state of knowledge using manganese oxide (MnOx)-based catalysts for toluene abatement in PPC (Post plasma-catalysis) configuration. The context of this study is concisely sum-up. After briefly screening the main depollution methods, the principles of PPC are exposed based on the coupling of two mature technologies such as NTP (Non thermal plasma) and catalysis. In that respect, the presentation of the abundant manganese oxides will be firstly given. Then in a second step the main features of MnOx allowing better performances in the reactions expected to occur in the abatement of toluene in PPC process are reviewed including ozone decomposition, toluene ozonation, CO oxidation and toluene total oxidation. Finally, in a last part the current status of the applications of PPC using MnOx on toluene abatement are discussed. In a first step, the selected variables of the hybrid process related to the experimental conditions of toluene abatement in air are identified. The selected variables are those expected to play a role in the performances of PPC system towards toluene abatement. Then the descriptors linked to the performances of the hybrid process in terms of efficiency are given and the effects of the variables on the experimental outcomes (descriptors) are discussed. The review would serve as a reference guide for the optimization of the PPC process using MnOx-based oxides for toluene abatement.

An in-Depth Investigation of Toluene Decomposition with a Glass Beads-Packed Bed Dielectric Barrier Discharge Reactor

Abstract: A glass beads-packed bed dielectric barrier discharge reactor is used for the removal of low concentration toluene (330 ppm) in air. The influence of relative humidity (RH) of the air on the discharge characteristics, toluene removal efficiency, and byproduct formation is examined. Optical emission spectroscopy has shown that the amount of N2 excited states decreases with increasing RH because of the increased quenching of these excited states. A toluene removal efficiency of 42 ± 2% was obtained at an optimum RH of 40% at a specific input energy of approximately 250 J/L. The main products of the toluene decomposition process were identified as CO2, CO, N2O, O3 (both dry and humid air) and HCOOH (dry air only). While higher RH suppresses the formation of formic acid, the highest CO and CO2 yields, N2O, and O3 concentrations at an RH of 40% confirm the observed highest removal efficiency at this experimental condition.

Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources.

Abstract: It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs), which are a major contributor to the formation of secondary pollutants (e.g., tropospheric ozone, PAN (peroxyacetyl nitrate), and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well-being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.

Highly efficient mesoporous MnO2 catalysts for the total toluene oxidation: Oxygen-Vacancy defect engineering and involved intermediates using in situ DRIFTS

Abstract: To elucidate the role of oxygen vacancy defects, various Mn-based oxides with oxygen vacancy defects are employed to the toluene oxidation, which are synthesized by adjusting solvent and double-complexation routes. The MnOx-ET catalyst shows the highest catalytic activity (T90 = 225 °C) for toluene oxidation. Compared with other Mn-based oxides, the as-prepared MnOx-ET catalyst has more surficial oxygen vacancies and good oxygen storage capacity (OSC), which is the reason on its remarkable activity for toluene oxidation. In addition, in situ DRIFTS study reveals that both lattice oxygen and adsorbed oxygen species can participate in the activation-oxidation process of toluene, which results in two reaction routes for the toluene oxidation. The rich oxygen-vacancy concentration of catalysts accelerates the key steps for the activation and generation of oxidized products. Quasi-in situ XPS results further confirm that enrich adsorbed-oxygen species as active oxygen and increasing Mn4+ concentration enhance the superior activity for toluene oxidation.

Multiple regression, ANN (RBF, MLP) and ANFIS models for prediction of swell potential of clayey soils

Abstract: Research highlights? The use of multiple regression (MR), artificial neural network (ANN) and artificial neuro-fuzzy inference system (ANFIS) models, for the prediction of swell percent of soils, was described and compared. ? However the accuracies of ANN and ANFIS models may be evaluated relatively similar, it is shown that the constructed ANN models of RBF and MLP exhibit a high performance than ANFIS and multiple regression for predicting swell percent of clays. ? The performance comparison showed that the soft computing system is a good tool for minimizing the uncertainties in the soil engineering projects. ? The use of soft computing will also may provide new approaches and methodologies, and minimize the potential inconsistency of correlations. In the recent years, new techniques such as; artificial neural networks and fuzzy inference systems were employed for developing of the predictive models to estimate the needed parameters. Soft computing techniques are now being used as alternate statistical tool. Determination of swell potential of soil is difficult, expensive, time consuming and involves destructive tests. In this paper, use of MLP and RBF functions of ANN (artificial neural networks), ANFIS (adaptive neuro-fuzzy inference system) for prediction of S% (swell percent) of soil was described, and compared with the traditional statistical model of MR (multiple regression). However the accuracies of ANN and ANFIS models may be evaluated relatively similar. It was found that the constructed RBF exhibited a high performance than MLP, ANFIS and MR for predicting S%. The performance comparison showed that the soft computing system is a good tool for minimizing the uncertainties in the soil engineering projects. The use of soft computing will also may provide new approaches and methodologies, and minimize the potential inconsistency of correlations.

Revealing the Highly Catalytic Performance of Spinel CoMn2O4 for Toluene Oxidation: Involvement and Replenishment of Oxygen Species Using In Situ Designed-TP Techniques

Abstract: The catalytic oxidation of toluene to CO2 and H2O over nanoflower spinel CoMn2O4 synthesized by the oxalic acid sol–gel method has been investigated, and it demonstrates lower activation energy (35...

Synthesis of CeaMnOx hollow microsphere with hierarchical structure and its excellent catalytic performance for toluene combustion

Abstract: A series of CeaMnOx hollow microsphere like arbutus with hierarchical structure are prepared by redox co-precipitation method and applied for catalytic toluene combustion. The Ce0.03MnOx shows a better catalytic performance for toluene combustion with high stability, water resistance, even under the condition of 5vol.% H2O. The results of XRF, XRD, Raman, N2 adsorption-desorption, SEM, TEM prove that the doping of Ce can affect the structure of CeaMnOx such as much smaller particle size and higher specific surface area. The characterizations of H2-TPR, O2-TPD, XPS certify the strong interaction between Ce and Mn oxides that leads to more surface adsorbed oxygen and Mn4+ species due to oxidation reduction cycle of Mn3+ + Ce4+ ↔ Mn4+ + Ce3+ after Ce addition. Meanwhile, the Toluene-TPD in different conditions confirms the introduction of water promoted the catalytic oxidation of toluene. In situ DRIFTS is used to investigate the reaction process of toluene oxidation. And the results reveal that the Ce0.03MnOx catalyst has much stronger ability to adsorb and activate toluene compared with MnOx catalyst, especially under with H2O. That may be the main reason that the Ce0.03MnOx catalyst exhibits the special catalytic activity for toluene combustion.