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Ammonia-mediated selective catalytic reduction (NH 3 -SCR) is currently the key approach to abate nitrogen oxides (NO x ) emitted from heavy-duty lean-burn vehicles. The state-of-art NH 3 -SCR catalysts, namely, copper ion-exchanged chabazite (Cu-CHA) zeolites, perform rather poorly at low temperatures (below 200 °C) and are thus incapable of eliminating effectively NO x emissions under cold-start conditions. Here, we demonstrate a significant promotion of low-temperature NO x reduction by reinforcing the dynamic motion of zeolite-confined Cu sites during NH 3 -SCR. Combining complex impedance-based in situ spectroscopy (IS) and extended density-functional tight-binding molecular dynamics simulation, we revealed an environment- and temperature-dependent nature of the dynamic Cu motion within the zeolite lattice. Further coupling in situ IS with infrared spectroscopy allows us to unravel the critical role of monovalent Cu in the overall Cu mobility at a molecular level. Based on these mechanistic understandings, we elicit a boost of NO x reduction below 200 °C by reinforcing the dynamic Cu motion in various Cu-zeolites (Cu-CHA, Cu-ZSM-5, Cu-Beta, etc.) via facile postsynthesis treatments, either in a reductive mixture at low temperatures (below 250 °C) or in a nonoxidative atmosphere at high temperatures (above 450 °C).

Phosphorus (P) stemming from biodiesel and/or lubricant oil additives is unavoidable in real diesel exhausts and deactivates gradually the Cu-SSZ-13 zeolite catalyst for ammonia-assisted selective catalytic NO x reduction (NH 3 -SCR). Here, the deactivation mechanism of Cu-SSZ-13 by P-poisoning was investigated by ex situ examination of the structural changes and by in situ probing the dynamics and redox of Cu active sites via a combination of impedance spectroscopy, diffuse reflection infrared Fourier transform spectroscopy, and ultraviolet-visible spectroscopy. We unveiled that strong interactions between Cu and P led to not only a loss of Cu active sites for catalytic turnovers but also a restricted dynamic motion of Cu species during low-temperature NH 3 -SCR catalysis. Furthermore, the Cu II ↔ Cu I redox cycling of Cu sites, especially the Cu I → Cu II reoxidation half-cycle, was significantly inhibited, which can be attributed to the restricted Cu motion by P-poisoning disabling the formation of key dimeric Cu intermediates. As a result, the NH 3 -SCR activity at low temperatures (200 °C and below) decreased slightly for the mildly poisoned Cu-SSZ-13 and considerably for the severely poisoned Cu-SSZ-13.

Reduction of harmful nitrogen oxides (NO x ) from diesel engine exhausts is one of the key challenges in environmental protection, and can be achieved by NH 3 -assisted selective catalytic reduction (NH 3 -SCR) using copper-exchanged chabazite zeolites (i.e. Cu-CHA, including Cu-SSZ-13 and Cu-SAPO-34) as catalysts. Understanding the redox chemistry of Cu-CHA in NH 3 -SCR catalysis is crucial for further improving the NO x reduction efficiency. Here, a series of Cu-SSZ-13 catalysts with different Cu ion exchange levels were prepared, thoroughly characterized by different techniques such as X-ray diffraction, diffuse reflectance ultraviolet-visible spectroscopy and temperature-programmed desorption using NH 3 as a probe molecule, etc., and tested in NH 3 -SCR reactions under steady-state conditions. In situ studies by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), supplemented with density-functional theory calculations, provided solid evidence for the formation of ammonium ion (NH 4 + ) intermediates resulting from the reduction of Cu 2+ to Cu + by co-adsorbed NH 3 and NO molecules on Cu-SSZ-13. Catalytic relevance of the NH 4 + intermediates, as demonstrated by an increase of NO conversion over Cu-SSZ-13 pre-treated in NH 3 /NO atmosphere, can be attributed to the formation of closely coupled Cu + /NH 4 + pairs promoting the Cu + re-oxidation and, consequently, the overall NH 3 -SCR process. This study thus paves a new route for improving the NH 3 -SCR efficiency over Cu-CHA zeolite catalyst., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Electroautotrophy is a novel and fascinating microbial metabolism, with tremendous potential for CO 2 storage and valorization into chemicals and materials made thereof. Research attention has been devoted toward the characterization of acetogenic and methanogenic electroautotrophs. In contrast, here we characterize the electrophysiology of a sulfate-reducing bacterium, Desulfosporosinus orientis , harboring the Wood-Ljungdahl pathway and, thus, capable of fixing CO 2 into acetyl-CoA. For most electroautotrophs the mode of electron uptake is still not fully clarified. Our electrochemical experiments at different polarization conditions and Fe 0 corrosion tests point to a H 2 - mediated electron uptake ability of this strain. This observation is in line with the lack of outer membrane and periplasmic multi-heme c -type cytochromes in this bacterium. Maximum planktonic biomass production and a maximum sulfate reduction rate of 2 ± 0.4 mM day -1 were obtained with an applied cathode potential of -900 mV vs. Ag/AgCl, resulting in an electron recovery in sulfate reduction of 37 ± 1.4%. Anaerobic sulfate respiration is more thermodynamically favorable than acetogenesis. Nevertheless, D. orientis strains adapted to sulfate-limiting conditions, could be tuned to electrosynthetic production of up to 8 mM of acetate, which compares well with other electroacetogens. The yield per biomass was very similar to H 2 /CO 2 based acetogenesis. Acetate bioelectrosynthesis was confirmed through stable isotope labeling experiments with Na-H 13 CO 3 . Our results highlight a great influence of the CO 2 feeding strategy and start-up H 2 level in the catholyte on planktonic biomass growth and acetate production. In serum bottles experiments, D. orientis also generated butyrate, which makes D. orientis even more attractive for bioelectrosynthesis application. A further optimization of these physiological pathways is needed to obtain electrosynthetic butyrate production in D. orientis biocathodes. This study expands the diversity of facultative autotrophs able to perform H 2 -mediated extracellular electron uptake in Bioelectrochemical Systems (BES). We characterized a sulfate-reducing and acetogenic bacterium, D. orientis , able to naturally produce acetate and butyrate from CO 2 and H 2 . For any future bioprocess, the exploitation of planktonic growing electroautotrophs with H 2 -mediated electron uptake would allow for a better use of the entire liquid volume of the cathodic reactor and, thus, higher productivities and product yields from CO 2 -rich waste gas streams., (Copyright © 2020 Agostino, Lenic, Bardl, Rizzotto, Phan, Blank and Rosenbaum.)

The concept to utilize a catalyst directly as a sensor is fundamentally and technically attractive for a number of catalytic applications, in particular, for the catalytic abatement of automotive emission. Here, we explore the potential of microporous copper-exchanged chabazite (Cu-CHA, including Cu-SSZ-13 and Cu-SAPO-34) zeolite catalysts, which are used commercially in the selective catalytic reduction of automotive nitrogen oxide emission by NH 3 (NH 3 -SCR), as impedance sensor elements to monitor directly the NH 3 -SCR process. The NH 3 -SCR sensing behavior of commercial Cu-SSZ-13 and Cu-SAPO-34 catalysts at typical reaction temperatures (i.e., 200 and 350 °C) was evaluated according to the change of ionic conductivity and was mechanistically investigated by complex impedance-based in situ modulus spectroscopy. Short-range (local) movement of Cu ions within the zeolite structure was found to determine largely the NH 3 -SCR sensing behavior of both catalysts. Formation of NH 3 -solvated, highly mobile Cu I species showed a predominant influence on the ionic conductivity of both catalysts and, consequently, hindered NH 3 -SCR sensing at 200 °C. Density functional theory calculations over a model Cu-SAPO-34 system revealed that Cu II reduction to Cu I by coadsorbed NH 3 and NO weakened significantly the coordination of the Cu site to the CHA framework, enabling high mobility of Cu I species that influences substantially the NH 3 -SCR sensing. The in situ spectroscopic and theoretical investigations not only unveil the mechanisms of Cu-CHA catalyst as sensor elements for direct NH 3 -SCR monitoring but also allow us to get insights into the speciation of active Cu sites in NH 3 -SCR under different reaction conditions with varied temperatures and gas compositions.

Purpose: To illustrate the out-of-pocket (OOP) costs incurred by a population-based group of patients from 5 to 10 years since their cancer diagnosis in a country with a nationwide public health system., Methods: Interviews on OOP costs to a sample of 5-10 year prevalent cases randomly extracted from four population-based cancer registries (CRs), two in the north and two in the south of Italy. The patients' general practitioners (GPs) gave assurance about the patient's physical and psychological condition for the interview. A zero-inflated negative binomial model was used to analyze OOP cost determinants., Results: Two hundred six cancer patients were interviewed (48 % of the original sample). On average, a patient in the north spent €69 monthly, against €244 in the south. The main differences are for transport, room, and board (TRB) to reach the hospital and/or the cancer specialist (north €0; south €119). Everywhere, OOP costs without TRB costs were higher for patients with a low quality of life., Conclusions: Despite the limited participation, our study sample's characteristics are similar to those of the Italian cancer prevalence population, allowing us to generalize the results. The higher OOP costs in the south may be due to the scarcity of oncologic structures, obliging patients to seek assistance far from their residence. Implications for cancer survivors Cancer survivors need descriptive studies to show realistic data about their status. Future Italian and European descriptive studies on cancer survivorship should be based on population CRs and involve GPs in order to approach the patient at best.