Light-driven nitrogen fixation routes for green ammonia production.

The global goal for decarbonization of the energy sector and the chemical industry could become a reality by a massive increase in renewable-based technologies. For this clean energy transition, the versatile green ammonia may play a key role in the future as a fossil-free fertilizer, long-term energy storage medium, chemical feedstock, and clean burning fuel for transportation and decentralized power generation. The high energy-intensive industrial ammonia production has triggered researchers to look for a step change in new synthetic approaches powered by renewable energies.

Light-Driven Nitrogen Fixation to Ammonia over Aqueous-Dispersed Mo-Doped TiO Colloidal Nanocrystals.

Photocatalytic nitrogen fixation to ammonia and nitrates holds great promise as a sustainable route powered by solar energy and fed with renewable energy resources (N and HO). This technology is currently under deep investigation to overcome the limited efficiency of the process. The rational design of efficient and robust photocatalysts is crucial to boost the photocatalytic performance.

Removal of NO at low concentration from air in urban built environments by activated miscanthus biochar.

This work presents an innovative and sustainable approach to remove NO emissions from urban ambient air in confined areas (underground parking areas or tunnels) using low-cost activated carbons obtained from Miscanthus biochar (MSP700) by physical activation (with CO or steam) at temperatures ranging from 800 to 900 °C. The NO removal capacity of the activated biochars was evaluated under different conditions (temperature, humidity and oxygen concentration) and compared against a commercial activated carbon. This last material showed a clear dependence on oxygen concentration and temperature, exhibiting a maximum capacity of 72.

Highly Active and Stable Ni/La-Doped Ceria Material for Catalytic CO Reduction by Reverse Water-Gas Shift Reaction.

The design of an active, effective, and economically viable catalyst for CO conversion into value-added products is crucial in the fight against global warming and energy demand. We have developed very efficient catalysts for reverse water-gas shift (rWGS) reaction. Specific conditions of the synthesis by combustion allow the obtention of macroporous materials based on nanosized Ni particles supported on a mixed oxide of high purity and crystallinity.

Mechanistic View of the Main Current Issues in Photocatalytic CO Reduction.

After 40 years of research on photocatalytic CO reduction, there are still many unknowns about its mechanistic aspects even for the most common TiO-based photocatalytic systems. These uncertainties include the pathways inducing visible-light activity in wide-band gap semiconductors, the charge transfer between semiconductors and plasmonic metal nanoparticles, the unambiguous determination of the origin of C-bearing products, the very first step in the activation of the CO molecule, the factors determining the selectivity, the reasons for photocatalyst deactivation, the closure of the catalytic cycle by the hole-scavenging reagent, and the detailed reaction pathways and the most suitable techniques for their determination. This Perspective discusses these controversial issues based on the most relevant investigations reported so far.

Unravelling the effect of charge dynamics at the plasmonic metal/semiconductor interface for CO photoreduction.

Sunlight plays a critical role in the development of emerging sustainable energy conversion and storage technologies. Light-induced CO reduction by artificial photosynthesis is one of the cornerstones to produce renewable fuels and environmentally friendly chemicals. Interface interactions between plasmonic metal nanoparticles and semiconductors exhibit improved photoactivities under a wide range of the solar spectrum.

Gas Phase Hydrogenation of Furaldehydes via Coupling with Alcohol Dehydrogenation over Ceria Supported Au-Cu.

We have investigated the synthesis and application of Au-Cu/CeO₂ (Cu: Au = 2) in the continuous gas phase ( 1 atm; = 498 K) coupled hydrogenation of 5-hydroxymethyl-2-furaldehyde (HMF) with 2-butanol dehydrogenation. STEM-EDX analysis revealed a close surface proximity of both metals in Au-Cu/CeO₂ -TPR. XPS measurements suggest (support → metal) charge transfer to form Au and strong metal-support interactions to generate Cu⁰ and Cu⁺.

Role of Support Oxygen Vacancies in the Gas Phase Hydrogenation of Furfural over Gold.

Abstract: We have examined the role of support oxygen vacancies in the gas phase hydrogenation of furfural over Au/TiO and Au/CeO prepared by deposition-precipitation. Both catalysts exhibited a similar Au particle size distribution (1-6 nm) and mean (2.8-3.

[Hibernoma: brown fat retroperitoneal tumor. Report of a pediatric case].

Hibernoma is a rare benign tumor of soft tissue, composed of brown fat. This tissue is predominant in hibernating animals and hence its name. Because of its rarity in Pediatrics and difficult diagnosis, we report a 3 month-old patient with a diagnosis consistent with an abdominal tumor.

Asymptomatic leukemic-cell infiltration of the pancreas: US findings.

Pancreatic infiltration of leukemic cells is a very rare manifestation at the onset of acute lymphoblastic leukemia (ALL) in childhood. Pancreatic enlargement in this situation is unusual and pancreatic involvement is often associated with biliary obstruction, cholestasis and pancreatitis. We report a 3-month-old girl who presented with asymptomatic leukemic infiltration of the pancreas, demonstrated by US with heterogeneous pancreatic enlargement associated with multiple hypoechogenic lesions, without cholestasis.