Monoethanolamine (MEA), a potential atmospheric pollutant from the capture unit of a leading CO capture technology, could be removed by participating HSO-based new particle formation (NPF) as simple amines. Here we evaluated the enhancing potential of MEA on HSO-based NPF by examining the formation of molecular clusters of MEA and HSO using combined quantum chemistry calculations and kinetics modeling. The results indicate that MEA at the parts per trillion (ppt) level can enhance HSO-based NPF. The enhancing potential of MEA is less than that of dimethylamine (DMA), one of the strongest enhancing agents, and much greater than methylamine (MA), in contrast to the order suggested solely by their basicity (MEA < MA < DMA). The unexpectedly high enhancing potential is attributed to the role of -OH of MEA in increasing cluster binding free energies by acting as both a hydrogen bond donor and acceptor. After the initial formation of one HSO and one MEA cluster, the cluster growth mainly proceeds by first adding one HSO, and then one MEA, which differs from growth pathways in HSO-DMA and HSO-MA systems. Importantly, the effective removal rate of MEA due to participation in NPF is comparable to that of oxidation by hydroxyl radicals at 278.15 K, indicating NPF as an important sink for MEA.

BACKGROUND: Endocrine disrupting chemicals (EDCs) are xenobiotics that mimic the interaction of natural hormones and alter synthesis, transport, or metabolic pathways. The prospect of EDCs causing adverse health effects in humans and wildlife has led to the development of scientific and regulatory approaches for evaluating bioactivity. This need is being addressed using high-throughput screening (HTS) in vitro approaches and computational modeling. OBJECTIVES: In support of the Endocrine Disruptor Screening Program, the U.S. Environmental Protection Agency (EPA) led two worldwide consortiums to virtually screen chemicals for their potential estrogenic and androgenic activities. Here, we describe the Collaborative Modeling Project for Androgen Receptor Activity (CoMPARA) efforts, which follows the steps of the Collaborative Estrogen Receptor Activity Prediction Project (CERAPP).

Amines are recognized as significant enhancing species on methanesulfonic acid (MSA)-driven new particle formation (NPF). Monoethanolamine (MEA) has been detected in the atmosphere and its concentration could be significantly increased once MEA-based post-combustion CO2 capture technology is widely implemented. Here, we evaluated the enhancing potential of MEA on MSA-driven NPF by examining the formation of MEA-MSA clusters using a combination of quantum chemical calculations and kinetics modeling. The results indicate that-OH group of MEA can form at least one hydrogen bond with MSA or MEA in all MEA-containing clusters. The enhancing potential of MEA is higher than that of the strongest enhancing agent known so far, methylamine (MA), for MSA-driven NPF. Such high enhancing potential can be ascribed to not only the higher gas-phase basicity, but also the role of the additional-OH group of MEA in increasing the binding free energy by forming additional hydrogen bonds. This clarifies the importance of hydrogen-bonding capacity from the non-amino group of amines in enhancing MSA-driven NPF. The main growth pathway for MEA-MSA clusters proceeds via the initial formation of the (MEA)1(MSA)1 cluster, followed by alternately adding one MSA and one MEA molecule, differing from the case of MA-MSA clusters.

Recent findings on the formation of ·Cl in continental urban areas necessitate the consideration of ·Cl initiated degradation when assessing the fate of volatile organic pollutants. Monoethanolamine (MEA) is considered as a potential atmospheric pollutant since it is a benchmark and widely utilized solvent in a leading CO2 capture technology. Especially, ·Cl may have specific interactions with the N atom of MEA, which could make the MEA + ·Cl reaction have different pathways and products from those of the MEA + ·OH reaction. Hence, ·Cl initiated reactions with MEA were investigated by a quantum chemical method [CCSD(T)/aug-cc-pVTZ//MP2/6-31+G(3df,2p)] and kinetics modeling. Results show that the overall rate constant for ·Cl initiated H-abstraction of MEA is 5 times faster than that initiated by ·OH, and the tropospheric lifetimes of MEA will be overestimated by 6-46% when assuming that [·Cl]/[·OH] = 1-10% if the role of ·Cl is ignored. The MEA + ·Cl reaction exclusively produces MEA-N that finally transforms into several products including mutagenic nitramine and carcinogenic nitrosamine via further reactions with O2/NOx, and the contribution of ·Cl to their formation is about 25-250% of that of ·OH. Thus, it is necessary to consider ·Cl initiated tropospheric degradation of MEA for its risk assessment.

Novel iron-tungsten catalysts were first developed for the selective catalytic reduction of NO by NH in diesel exhaust, achieving an excellent performance with a wide operating temperature window above 90% NO conversion from 225 or 250 to 450 °C (GHSVs of 30 000 or 50 000 h). It also exhibited a pronounced stability and relatively high NO conversion in the presence of HO, SO and CO. The introduction of W resulted in the formation of α-FeO and FeWO species obtained by HRTEM directly. The synergic effect of two species contributed to the high SCR activity, because of the increased surface acidity and electronic property. The FeWO with octahedral [FeO]/[WO] structure acted as the Brønsted acid sites to form highly active NH species. Combining DFT calculations with XPS and UV-vis results, it was found that the fine electron interaction between α-FeO and FeWO made the electron more easily transfer from W sites to Fe sites, which promoted the formation of NO. Judging by the kinetics and SCR activity studies, the FeWO with an appropriate W amount showed the strongest interaction, and thereby the lowest activation energy of 39 kJ•mol and optimal catalytic activity. These findings would be conducive to the reasonable design of NH-SCR catalysts by adjusting the fabrication.