Enhancing ozone catalytic decomposition through acid treatment of α-MnO for improved activity and humidity resistance.

Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts. Here the α-MnO catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid.

Reverse oxygen spillover triggered by CO adsorption on Sn-doped Pt/TiO for low-temperature CO oxidation.

The spillover of oxygen species is fundamentally important in redox reactions, but the spillover mechanism has been less understood compared to that of hydrogen spillover. Herein Sn is doped into TiO to activate low-temperature (<100 °C) reverse oxygen spillover in Pt/TiO catalyst, leading to CO oxidation activity much higher than that of most oxide-supported Pt catalysts. A combination of near-ambient-pressure X-ray photoelectron spectroscopy, in situ Raman/Infrared spectroscopies, and ab initio molecular dynamics simulations reveal that the reverse oxygen spillover is triggered by CO adsorption at Pt sites, followed by bond cleavage of Ti-O-Sn moieties nearby and the appearance of Pt species.

Advances in the treatment of multi-pollutant flue gas in China's building materials industry.

In most of the world's building material industries, the control of flue gas pollutants mainly focuses on a single pollutant. However, given the large capacity and high contribution of China's building materials industry to global air pollution, the need to develop multi-pollutant emission reduction technology is urgent. Recently, China has focused on reducing the emissions of flue gas pollutants in the building materials industry, established many key research and development projects, and gradually implemented more stringent pollutant emission limits.

Structure-Directing Role of Support on Hg Oxidation over VO/TiO Catalyst Revealed for NO and Hg Simultaneous Control in an SCR Reactor.

The crystal structure of TiO strongly influences the physiochemical properties of supported active sites and thus the catalytic performance of the as-synthesized catalyst. Herein, we synthesized TiO with different crystal forms (R = rutile, A = anatase, and B = brookite), which were used as supports to prepare vanadium-based catalysts for Hg oxidation. The Hg oxidation efficiency over VO/TiO-B was the best, followed by VO/TiO-A and VO/TiO-R.

Like Cures like: Detoxification Effect between Alkali Metals and Sulfur over the VO/TiO deNO Catalyst.

The VO/TiO (VTi) catalyst has been widely employed for the NH selective catalytic reduction (NH-SCR) reaction, and sulfur (S) and alkali metals (K) were usually considered as poisons during this reaction. In this work, the synergistic effect of S and K over the VTi catalyst for the NH-SCR reaction was analyzed and discussed. It is surprisingly observed that the synergistic effects of S and K exhibited a detoxification effect on the NH-SCR reaction.

Dual Active Centers Bridged by Oxygen Vacancies of Ruthenium Single-Atom Hybrids Supported on Molybdenum Oxide for Photocatalytic Ammonia Synthesis.

Photocatalytic synthesis of ammonia (NH ) holds significant potential compared with the Haber-Bosch process. However, the reported photocatalysts suffer from low efficiency owing to localized electron deficiency. Herein, Ru-SA (single atoms)/H MoO hybrids with abundant of Mo (4 View Article and Find Full Text PDF

In Situ Modulation of A-Site Vacancies in LaMnO Perovskite for Surface Lattice Oxygen Activation and Boosted Redox Reactions.

Modulation of A-site defects is crucial to the redox reactions on ABO perovskites for both clean air application and electrochemical energy storage. Herein we report a scalable one-pot strategy for in situ regulation of La vacancies (V ) in LaMnO by simply introducing urea in the traditional citrate process, and further reveal the fundamental relationship between V creation and surface lattice oxygen (O ) activation. The underlying mechanism is shortened Mn-O bonds, decreased orbital ordering, promoted MnO bending vibration and weakened Jahn-Teller distortion, ultimately realizing enhanced Mn-3d and O-2p orbital hybridization.

Boosting the Catalytic Performance of CeO in Toluene Combustion via the Ce-Ce Homogeneous Interface.

Catalytic combustion is an advanced technology to eliminate industrial volatile organic compounds such as toluene. In order to replace the expensive noble metal catalysts and avoid the aggregation phenomenon occurring in traditional heterogeneous interfaces, designing homogeneous interfaces can become an emerging methodology to enhance the catalytic combustion performance of metal oxide catalysts. A mesocrystalline CeO catalyst with abundant Ce-Ce homogeneous interfaces is synthesized a self-flaming method which exhibits boosted catalytic performance for toluene combustion compared with traditional CeO, leading to a ∼40 °C lower T.

Penetration of Arsenic and Deactivation of a Honeycomb VO-WO/TiO Catalyst in a Glass Furnace.

Deactivation of honeycomb VO-WO/TiO catalysts by arsenic has been studied widely in coal-fired power plants but rarely in glass furnaces. In this paper, deactivated catalysts that had been used for more than 4000 h were analyzed. We maintained the catalysts in their original monolith shape to retain their adhered substance and used appropriate methods to strip the substance layer by layer.

Balance of activation and ring-breaking for toluene oxidation over CuO-MnO bimetallic oxides.

CuMn oxides have been studied for many years to catalytic degradation of toluene, but there are still many divergences on the essence of their great catalytic activity and reaction mechanism. A series of CuMn bimetallic oxides were synthesized for the catalytic oxidation of toluene in this study. CuMn exhibited the highest toluene oxidation rate per specific surface area, which was approximately 4 times that of monometallic CuO and MnO.

Roles of Oxygen Vacancies in the Bulk and Surface of CeO for Toluene Catalytic Combustion.

Catalytic combustion technology is one of the effective methods to remove VOCs such as toluene from industrial emissions. The decomposition of an aromatic ring via catalyst oxygen vacancies is usually the rate-determining step of toluene oxidation into CO. Series of CeO probe models were synthesized with different ratios of surface-to-bulk oxygen vacancies.

Balance between Reducibility and NO Adsorption Capacity for the NO Decomposition: CuCo Catalysts as an Example.

CuCo (CuO-CoO mixed oxides) catalysts were prepared via co-precipitation for the NO decomposition reaction. They exhibited a higher NO decomposition activity than that of pure CuO and CoO because of the balance of the redox property and NO adsorption capacity. CoO presented a large number of surface oxygen vacancies, increasing the NO chemical adsorption as "□-Co-ON" on the catalyst surface, whereas CuO was dispersed around CoO and presented high reducibility on the interface of CoO-CuO for the N-O break of NO, healing oxygen vacancies by leaving one oxygen atom in the vacancy.

Performance of Modified La SrMnO Perovskite Catalysts for NH Oxidation: TPD, DFT, and Kinetic Studies.

The modified perovskites (La SrMnO) were prepared using the selective dissolution method for the selective catalytic oxidation (SCO) of NH. We found that more Mn cations and active surface oxygen species formed on the catalyst's surface with increasing the dissolution time (dis). The 1h-dis catalyst exhibited excellent NH conversion, and it performed well in the presence of SO and HO.

HS-Modified Fe-Ti Spinel: A Recyclable Magnetic Sorbent for Recovering Gaseous Elemental Mercury from Flue Gas as a Co-Benefit of Wet Electrostatic Precipitators.

The nonrecyclability of the sorbents used to capture Hg from flue gas causes a high operation cost and the potential risk of exposure to Hg. The installation of wet electrostatic precipitators (WESPs) in coal-fired plants makes possible the recovery of spent sorbents for recycling and the centralized control of Hg pollution. In this work, a HS-modified Fe-Ti spinel was developed as a recyclable magnetic sorbent to recover Hg from flue gas as a co-benefit of the WESP.

Elemental Mercury Oxidation over Fe-Ti-Mn Spinel: Performance, Mechanism, and Reaction Kinetics.

The design of a high-performance catalyst for Hg oxidation and predicting the extent of Hg oxidation are both extremely limited due to the uncertainties of the reaction mechanism and the reaction kinetics. In this work, Fe-Ti-Mn spinel was developed as a high-performance catalyst for Hg oxidation, and the reaction mechanism and the reaction kinetics of Hg oxidation over Fe-Ti-Mn spinel were studied. The reaction orders of Hg oxidation over Fe-Ti-Mn spinel with respect to gaseous Hg concentration and gaseous HCl concentration were approximately 1 and 0, respectively.

Recyclable Naturally Derived Magnetic Pyrrhotite for Elemental Mercury Recovery from Flue Gas.

Magnetic pyrrhotite, derived from the thermal treatment of natural pyrite, was developed as a recyclable sorbent to recover elemental mercury (Hg) from the flue gas as a cobenefit of wet electrostatic precipitators (WESP). The performance of naturally derived pyrrhotite for Hg capture from the flue gas was much better than those of other reported magnetic sorbents, for example Mn-Fe spinel and Mn-Fe-Ti spinel. The rate of pyrrhotite for gaseous Hg capture at 60 °C was 0.

The centralized control of elemental mercury emission from the flue gas by a magnetic rengenerable Fe-Ti-Mn spinel.

A magnetic Fe-Ti-Mn spinel was developed to adsorb gaseous Hg(0) in our previous study. However, it is currently extremely restricted in the control of Hg(0) emission from the flue gas for at least three reasons: sorbent recovery, sorbent regeneration and the interference of the chemical composition in the flue gas. Therefore, the effect of SO2 and H2O on the adsorption of gaseous Hg(0) on the Fe-Ti-Mn spinel and the regeneration of spent Fe-Ti-Mn spinel were investigated in this study.

Mechanism of N2O formation during the low-temperature selective catalytic reduction of NO with NH3 over Mn-Fe spinel.

The mechanism of N2O formation during the low-temperature selective catalytic reduction reaction (SCR) over Mn-Fe spinel was studied. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and transient reaction studies demonstrated that the Eley-Rideal mechanism (i.e.