Study on the mechanism of acid treatment LaSrMnCuO to improve the catalytic activity of formaldehyde at low temperature.

To address the issue of surface enrichment of A-site ions in perovskite and the resulting suppression of catalytic activity, the LaSrMnCuO was modified by treatment with dilute nitric acid (2 mol/L) and dilute acetic acid (2 mol/L). The results show that the effect of dilute nitric acid treatment on the morphology and catalytic activity of the catalyst is more significant. The specific surface area of the catalyst after dilute nitric acid treatment (268.

Modeling the mechanisms of conifer mortality under seawater exposure.

Relative sea level rise (SLR) increasingly impacts coastal ecosystems through the formation of ghost forests. To predict the future of coastal ecosystems under SLR and changing climate, it is important to understand the physiological mechanisms underlying coastal tree mortality and to integrate this knowledge into dynamic vegetation models. We incorporate the physiological effect of salinity and hypoxia in a dynamic vegetation model in the Earth system land model, and used the model to investigate the mechanisms of mortality of conifer forests on the west and east coast sites of USA, where trees experience different form of sea water exposure.

Oxidation mechanism of HCHO on copper-manganese composite oxides catalyst.

Formaldehyde (HCHO) is a typical air pollutant that severely endangers human health. The Cu-Mn spinel-structure catalyst exhibits good catalytic oxidation activity for HCHO removal. Theoretical calculation study of density functional theory (DFT) was performed to provide an atomic-scale understanding for the oxidation mechanism of HCHO over CuMnO surface.

Mechanistic insights into benzene oxidation over CuMnO catalyst.

The spinel-type CuMnO catalyst exhibits good catalytic activity towards benzene oxidation, but the catalytic oxidation mechanism is not established. Theoretical calculations were implemented to unearth the reaction mechanism of benzene catalytic oxidation over CuMnO catalyst through density functional theory (DFT). The results indicate that benzene adsorption on both Cu-terminated and Mn-terminated surfaces are controlled by the chemisorption mechanism.

Mercury/oxygen reaction mechanism over CuFeO catalyst.

CuFeO is regarded as a promising candidate of catalyst for Hg oxidation in industrial flue gas. However, the microcosmic reaction mechanism governing mercury oxidation on CuFeO remains elusive. Herein, experiments and quantum chemistry calculations were conducted for understanding the chemical reaction mechanism of oxygen-assisted mercury oxidation on CuFeO.

Understanding A-site tuning effect on formaldehyde catalytic oxidation over La-Mn perovskite catalysts.

A combination study of density functional theory (DFT) calculation and microkinetic analysis was carried out to investigate A-site tuning effect on formaldehyde (HCHO) oxidation over La-Mn perovskite catalysts (A = Sr, Ag, and Sn). The oxygen mobility of A-doped LaMnO catalysts and reaction mechanism of HCHO oxidation on catalyst surfaces were investigated. The microkinetic simulation was performed to quantitatively determine the activity of catalysts toward the HCHO catalytic oxidation.

Nanosized Cu-In spinel-type sulfides as efficient sorbents for elemental mercury removal from flue gas.

Mercury emitted from human activities has received increasing attention because of its extreme toxicity, persistence and bioaccumulation. The development of highly-efficient sorbent with abundant active sites that exhibit high affinity toward Hg is the key challenge for elemental mercury capture at low temperature. Herein, Cu-In spinel-type sulfides were synthesized through a hydrothermal synthesis.

Reaction mechanism of dichloromethane oxidation on LaMnO perovskite.

The reaction mechanism of dichloromethane (CHCl) oxidation on LaMnO catalyst was investigated using density functional theory calculations. The results showed that CHCl dechlorination proceeds via CHCl → CHClO → HCHO. The adsorbed Cl∗ and formaldehyde (HCHO) are identified as the important intermediates of CHCl dechlorination process.

Charge-distribution modulation of copper ferrite spinel-type catalysts for highly efficient Hg oxidation.

Hg catalytic oxidation is an attractive approach to reduce mercury emissions from industrial activities. However, the rational design of highly active catalysts remains a significant challenge. Herein, the charge distribution modulation strategy was proposed to design novel catalysts: copper ferrite spinel-type catalysts were developed by introducing Cu cations into octahedral sites to form electron-transfer environment.

Optimization of leaf morphology in relation to leaf water status: A theory.

The leaf economic traits such as leaf area, maximum carbon assimilation rate, and venation are all correlated and related to water availability. Furthermore, leaves are often broad and large in humid areas and narrower in arid/semiarid and hot and cold areas. We use optimization theory to explain these patterns.

Catalytic reaction mechanism of formaldehyde oxidation by oxygen species over Pt/TiO catalyst.

Theoretical calculations based on density functional theory (DFT) were employed to uncover the molecular-level oxidation mechanism of HCHO over Pt/TiO surface. All the three possible reaction mechanisms including Eley-Rideal mechanism, Langmuir-Hinshelwood mechanism and Mars-Van Krevelen mechanism were deeply investigated to determine the primary channel of HCHO oxidation on Pt/TiO catalyst. The adsorption energies and geometries show that HCHO and O are chemically adsorbed on Pt and Ti sites of the Pt/TiO catalyst surface, respectively.

A complete catalytic reaction scheme for Hg oxidation by HCl over RuO/TiO catalyst.

RuO-based catalysts have attracted great attention in mercury emission control region due to their outstanding catalytic activity and long-term stability. Quantum chemistry calculation was performed to uncover the atomic-scale reaction mechanism of Hg oxidation by HCl over RuO/TiO catalyst. The results indicate that Hg adsorption on RuO/TiO(110) surface is controlled by a weak chemisorption mechanism.