Scientific Highlights from Research Division Energy and Environment
(ENE)
Scientific Highlights
Brennstoffzellen zum Durchbruch verhelfen
Wasserstoff gilt als vielversprechende Alternative für eine Zukunft ohne fossile Energieträger. Um Brennstoffzellen weiterzuentwickeln und für einen Markteintritt vorzubereiten, verstärkt die Empa die Zusammenarbeit mit der H2 Energy Holding AG und dem Paul Scherrer Institut (PSI).
Light from the particle accelerator helps to understand ozone decomposition
PSI researchers have developed an experimental chamber in which they can recreate atmospheric processes and probe them with unprecedented precision, using X-ray light from the Swiss Light Source SLS. In the initial experiments, they have studied the production of bromine, which plays an essential role in the decomposition of ozone in the lower layers of the atmosphere. In the future, the new experiment chamber will also be available for use by researchers from other scientific fields.
Coexistence of Physisorbed and Solvated HCl at Warm Ice Surfaces
The interfacial ionization of strong acids is an essential factor of multiphase and heterogeneous chemistry in environmental science, cryospheric science, catalysis research and material science. Using Near Ambient Pressure X-ray Photoelectron (NAPP) spectroscopy, we directly detected a low surface coverage of adsorbed HCl at 253 K in both molecular and dissociated states and interpret the results as physisorbed molecular HCl at the outermost ice surface and dissociation occurring upon solvation deeper in the interfacial region. This study gives clear evidence for nonuniformity across the air−ice interface and questions the use of acid−base concepts in interfacial processes.
Gasoline cars produce more carbonaceous particulate matter than modern filter-equipped diesel cars
In contrast to nitrogen oxides, modern gasoline cars emit much more cancerogenic primary soot (black carbon + primary organic aerosol) and lead to more toxic secondary organic aerosol than modern diesel vehicles.
Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago
Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Based on a 6500 year ice-core Cu record from Illimani glacier in Bolivia we provide the first complete history of large-scale Cu smelting activities in South America. Earliest anthropogenic Cu pollution was found during the Early Horizon period ~700-50 BC. We attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.
Nanotechnology enables new insights into chemical reactions
Eighty percent of all products of the chemical industry are manufactured with catalytic processes. Catalysis is also indispensable in energy conversion and treatment of exhaust gases. Industry is always testing new substances and arrangements that could lead to new and better catalytic processes. Researchers of the Paul Scherrer Institute PSI in Villigen and ETH Zurich have now developed a method for improving the precision of such experiments, which may speed up the search for optimal solutions.
The substances that brighten up the clouds
Clouds consist of tiny droplets. These droplets form when water condenses around so-called aerosols – small particles in the atmosphere. To understand how in turn aerosols come into existence scientists have now created a comprehensive computer model simulation based on profound experimental data. This simulation revealed that in addition to sulphuric acid, two other substances are crucially involved in the formation of aerosols: organic compounds and ammonia. These results have now been published in the renowned journal Science.
Labile peroxides in secondary organic aerosol
Aerosols, suspended fine liquid or solid particles in the air we breathe, play a central role in many environmental processes through their influence on climate, the hydrological cycle, and their adverse effects on human health. While the mechanisms by which aerosol particles affect our health remain uncertain, the atmospheric oxidation of organic vapors has been shown to be related to the formation of oxygenated organic matter with high oxidative potential, the so-called reactive oxygen species (ROS).
Sun-Petrol
Despite its great potential, solar energy still faces one big problem: the sun doesn’t always shine and its energy is hard to store. Now, researchers at the Paul Scherrer Institute PSI and the ETH Zurich have unveiled a chemical process that uses the sun’s thermal energy to convert carbon dioxide and water directly into high-energy fuels: a procedure developed on the basis of a ground-breaking material combination of cerium oxide and rhodium.