A quasi chemical vapor deposition method for the manufacture of well-defined covalent triazine framework (CTF) coatings on cordierite monoliths is reported. The resulting supported porous organic polymer is an excellent support for the immobilization of two different homogeneous catalysts: (1) an IrIIICp∗-based catalyst for the hydrogen production from formic acid and (2) a PtII-based catalyst for the direct activation of methane via Periana chemistry. The immobilized catalysts display a much higher activity in comparison with the unsupported CTF operated in slurry because of improved mass transport. Our results demonstrate that CTF-based catalysts can be further optimized by engineering at different length scales.@en

Temporal analysis of product (TAP) is used to investigate the effectiveness of CO, C3H6, and C3H8 in the reduction of a La–Zr doped ceria catalyst and NO reduction into N2 over this pre-reduced catalyst. Hydrocarbons are found to be substantially more effective in the reduction of this catalyst at high temperature (above 500 °C) as compared to CO. NO decomposes over oxygen anion defects created upon catalyst reduction. Deposited carbon, in case the catalyst is reduced by C3H6 or C3H8, acts as a delayed or stored reductant and is not directly involved in NO reduction. Instead the oxidation of deposited carbon by an oxygen species derived from lattice oxygen (re)creates the oxygen anion defects active in NO reduction. In situ Raman, in which NO is flown over C3H6 pre-reduced La–Zr doped ceria at 560 °C, additionally shows that re-oxidation of the La–Zr doped ceria catalyst starts prior to the oxidation of deposited carbon, which confirms our TAP findings that firstly NO re-oxidized the La–Zr doped ceria catalyst and that secondly the oxidation of deposited carbon only commences at a higher ceria oxidation state. These findings create a new perspective on the operating principle of Toyota’s Di-Air system.@en

Ceria-based catalysts with different topological and textural properties have been prepared to study the role of the soot-catalyst contact on the soot oxidation reaction. The physico-chemical features of the catalysts have been investigated by means of complementary techniques, such as powder XRD, N2 physisorption at -196 °C, optical microscopy at variable temperature, FESEM, TEM, and thermogravimetric analysis.As a whole, the best catalytic activity has been obtained with the CeO2-nanocubes (denoted to as "Ce-NC") because of their higher intrinsic reactivity. On the other hand, high-surface area materials prepared by the cerium nitrate decomposition (denoted to as "Ce-ND") or hydrothermal route (CeO2-stars, referred to as "Ce-SAS") resulted less effective toward the soot combustion, confirming the surface-sensitivity for this reaction.Moreover, it has been proven a higher dependence of the oxidation activity on the catalyst-to-soot ratio (wt./wt.) for the nanostructured catalyst (Ce-NC) exhibiting the lowest BET specific surface area (SBET = 4 m2 g-1). On the other hand, the accessible (real) surface area, at variance of the BET surface area, seems to play a relevant role for this solid-solid reaction mediated by gas-phase oxygen.@en

The use of two different classes of covalent organic frameworks (covalent triazine and imine linked frameworks) as supports for molecular Ni2+ catalysts is presented. For COFs, a large concentration of N heteroatoms, either in the form of quasi bipyridine or as diiminopyridine moieties, allows for the coordination of NiBr2 to the scaffold of the porous polymers. When applied as catalysts in the oligomerization of ethylene under mild reaction conditions (15 bar, 50 °C), these new catalysts display an activity comparable to those of their homogeneous counterpart and a fivefold higher selectivity to C6 + olefins. Accumulation of long chain hydrocarbons within the porosity of the COFs leads to reversible deactivation. Full activity and selectivity of the best catalysts can be recovered upon washing with dichlorobenzene.@en

tA series of Fe-Ti mixed oxide model catalysts containing different Ti/Fe ratios were synthesized andapplied as catalysts for the High Temperature Fischer-Tropsch reaction (HTFTS). XRD, H2-TPR and in situMössbauer and XAFS spectroscopy were applied to evaluate the role of Ti on the physical and chemicalproperties of Fe within the mixed metal oxide. It was observed that the Ti/Fe ratio determines the relativeamounts of hematite, pseudobrookite, and anatase in the starting materials. The interplay between thesephases is responsible for the HTFTS catalytic performance.Our results demonstrate that the presence of pseudobrookite: i) enhances the dispersion of iron; ii)mediates and controls the reduction and carburization degree during the transformation of Fe (III) speciesto carbides upon activation, and iii) increases the stability under HTFTS conditions by minimizing the re-oxidation of iron carbides. Highest catalytic activity and stability is achieved for the material with Ti/Feratio of 1/2.1.@en

Currently commercial NOx removal (DeNOx) abatement systems for lean-burn engines exceed regulation limits on the road for NOx emissions. Commercial DeNOx catalysts exhibit poor performance in the selective conversion of NO to N2, especially at high temperature and high gas hourly space velocities (GHSV). In this study, oxygen vacancies of reduced ceria and Pt/ or Rh/ceria are found to be the efficient and selective catalytic sites for NO reduction to N2. Even at low concentrations, NO can compete with an excess of O2 at 600 °C and a high GHSV of 170 000 L L−1 h−1, conditions in which SCR and NSR DeNOx system are not able to function well. N2O is not detected over the whole range of conditions, whereas NO2 is only formed upon oxidation of the catalyst, after both NO and O2 start to appear. For consideration of the fuel economy, the working temperature should be between 250 and 600 °C. Above 600 °C, most of the injected fuel was combusted with O2. Below 250 °C, ceria support will not be reduced by fuel and the oxidation rate of the deposited carbon through oxygen from ceria lattice will be too low.@en

Background: Inhalation of particulate matter, as part of air pollution, is associated with increased morbidity and mortality. Nanoparticles (< 100nm) are likely candidates for triggering inflammatory responses and activation of coagulation pathways because of their ability to enter lung cells and pass bronchial mucosa. We tested the hypothesis that bronchial segmental instillation of carbon nanoparticles causes inflammation and activation of coagulation pathways in healthy humans in vivo. Methods: This was an investigator-initiated, randomized controlled, dose-escalation study in 26 healthy males. Participants received saline (control) in one lung segment and saline (placebo) or carbon nanoparticles 10μg, 50μg, or 100μg in the contra-lateral lung. Six hours later, blood and bronchoalveolar lavage fluid (BALF) was collected for inflammation and coagulation parameters. Results: There was a significant dose-dependent increase in blood neutrophils (p=0.046) after challenge with carbon nanoparticles. The individual top-dose of 100μg showed a significant (p=0.05) increase in terms of percentage neutrophils in blood as compared to placebo. Conclusions: This study shows a dose-dependent effect of bronchial segmental challenge with carbon nanoparticles on circulating neutrophils of healthy volunteers. This suggests that nanoparticles in the respiratory tract induce systemic inflammation. Trial registration: Dutch Trial Register no. 2976. 11 July 2011. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2976@en

Oxygen defects in reduced ceria are the catalytic sites for the NO reduction into N2 in the Toyota Di-Air DeNOx abatement technology. Traces of NO (several hundred ppm) have to compete with the excess amount of other oxidants, e.g., 5% CO2 and 5% O2, in an exhaust gas of a lean burn (diesel) engine. The reactivities of CO2 and NO over a reduced ceria and noble metal loaded reduced ceria have been investigated under ultra-high vacuum system in TAP and under atmosphere pressure in in-situ Raman and flow reactor set-up. The results showed that CO2 was a mild oxidant which was able to oxidise the oxygen defects, but hardly oxidised deposited carbon over both ceria and noble metal loaded ceria. NO was a stronger oxidant and more efficient in refilling the oxygen defects and able to convert the deposited carbon, which acted as buffer reductant to extend the NO reduction time interval. NO was selectively and completely converted into N2. The presence of excess CO2 hardly affected the NO reduction process into N2.@en

In this study, the role of the noble metals Pt and Rh (0.5 wt.%) for the selective reduction of NO into N2 is evaluated by the transient TAP technique and in-situ spectroscopy using a commercial stable ceria support (denoted as CZ) and applying isotopically labelled 15NO and 18O2. The transient operation was mimicked by multi-pulse oxidation (using O2 or NO) and reduction cycles (using CO, H2, C3H6 and C3H8), while following quantitatively the catalyst and reactants response. Pt and Rh significantly lowered the temperature of CZ reduction. CO and H2 only reduce the surface of CZ, while a 2.5 times deeper reduction was achieved by the hydrocarbons C3H6 and C3H8, removing also lattice oxygen. Pt and Rh also promoted carbon deposition after surface reduction. Rh was a more active promoter than Pt, while propene was more reactive than propane over both metals. During the NO reduction the pre-reduced CZ support became gradually re-oxidised and after filling 70–80% of the oxygen vacancies the NO started to appear in the product mixture. In the presence of carbon deposits the lattice oxygen of the CZ reacted with the carbon keeping the CZ in a reduced state, extending the NO decomposition process as long as the carbon was present. The reduction of NO over pre-reduced noble metal/CZ showed a selective formation N2, while N2O and NO2 were never observed. During the NO reduction process some unidentified N-species remained on the catalyst, the amount depending on the type of catalyst, but finally all nitrogen was released as N2. The presence of the noble metal led less unidentified N-species on the CZ surface and to a faster N2 formation rate than that over the bare CZ.@en

A membrane reactor containing an immobilized heterogeneous catalyst is an alternative for traditional homogeneous-based catalyzed transesterification for biodiesel production. Major problems in homogeneous catalysis are related to catalyst recuperation and soap formation, which can be overcome by using heterogeneous catalysts. Conversion can be increased by a combination of reaction and separation, using membranes with a specific pore size. The aim of this work was to study the performance of different membrane reactors combined with heterogeneous catalysis. The main objectives were: to identify a proper catalyst, to choose the proper immobilization technique, to establish the membrane with the adequate pore size, and to control the reaction and separation process. Amberlyst®15 with acid sites and different types of strontium oxide with basic sites were tested as heterogeneous catalysts. Strontium oxide provided the highest sunflower oil conversion (around 93%) and was easy to immobilize. Two catalytic membrane reactor configurations were investigated, thus confirming the production of several types of methyl esters. The configuration comprising the physical immobilization of the catalyst over the membrane reached a methyl ester yield of > 90 wt%.@en

Background: Clinical studies investigating medicinal products need to comply with laws concerning good clinical practice (GCP) and good manufacturing practice (GMP) to guarantee the quality and safety of the product, to protect the health of the participating individual and to assure proper performance of the study. However, there are no specific regulations or guidelines for non-Medicinal Investigational Products (non-MIPs) such as allergens, enriched food supplements, and air pollution components. As a consequence, investigators will avoid clinical research and prefer preclinical models or in vitro testing for e.g. toxicology studies. The aim of this article is to: 1) briefly review the current guidelines and regulations for Investigational Medicinal Products; 2) present a standardised approach to ensure the quality and safety of non-MIPs in human in vivo research; and 3) discuss some lessons we have learned. Methods and results: We propose a practical line of approach to compose a clarifying product dossier (PD), comprising the description of the production process, the analysis of the raw and final product, toxicological studies, and a thorough risk-benefit-analysis. This is illustrated by an example from a human in vivo research model to study exposure to air pollutants, by challenging volunteers with a suspension of carbon nanoparticles (the component of ink cartridges for laser printers). Conclusion: With this novel risk-based approach, the members of competent authorities are provided with standardised information on the quality of the product in relation to the safety of the participants, and the scientific goal of the study.@en

Sulfur addition is used to probe the role of gold in Au/Fe2O3/ZrO2 catalyst in the water-gas shift (WGS) at high temperature (623-773 K) and pressure (21 bar). Sulfur poisoning unravels the WGS activity contribution by gold nano-particles and gold promotion of iron oxide in Au/Fe2O3/ZrO2. The active site(s) on gold nano-particles are poisoned by sulfur, which is reflected in a suppressed WGS activity of presulfided Au/ZrO2. The same holds for the WGS activity contribution of gold nano-particles in Au/Fe2O3/ZrO2, but the promotion by gold of the Fe2O3 is still present after presulfidation. The WGS performance of Fe2O3/ZrO2 and Au/ZrO2 catalysts with and without sulfur pretreatment are also compared with that of Au/Fe2O3/ZrO2.@en

A facile one-step method to shape covalent triazine frameworks (CTFs) for catalytic applications is reported. Phase inversion of the CTF powder by using a polyimide as a binder in a microfluidic device results in the formation of composite spheres with accessible CTF porosity and a high mechanical and thermal stability. The fabricated spheres can be used to host organometallic complexes. The obtained shaped catalysts, Ir@CTF spheres, are active and fully recyclable in the direct hydrogenation of carbon dioxide into formic acid under mild reaction conditions (20 bar and 50–90 °C) and in the dehydrogenation of formic acid.@en