green technology – Lightsources.org

Using reed waste for sustainable batteries

2019/08/062019/09/19

With the changing climate, researchers are focusing on finding sustainable alternatives to conventional fuel cells and battery designs. Traditional catalysts used in vehicles contribute to increasing carbon dioxide emissions and mining for materials used in their design has a negative impact on the environment. Prof. Shuhui Sun, a researcher from the Institut National de la Recherche Scientifique (INRS) in Montreal, and his team used the Canadian Light Source (CLS) at the University of Saskatchewan to investigate an Iron-Nitrogen-Carbon catalyst using reed waste.

They hope to use the bio-based materials to create high-performance fuel cells and metal-air batteries, which could be used in electric cars. “An efficient oxygen electrocatalyst is extremely important for the development of high-performance electrochemical energy conversion and storage devices. Currently, the rare and expensive Pt-based catalysts are commonly used in these devices. Therefore, developing highly efficient and low-cost non-precious metal (e.g., Fe-based) catalysts to facilitate a sluggish cathodic oxygen reduction reaction (ORR) is a key issue for metal air batteries and fuel cells,” said Qilang Wei, the first author of the paper.

A step closer to smart catalysts for fuel generation

2019/07/222019/09/20

Researchers at the Universidade Federal do Rio Grande do Sul in Brazil in collaboration with the ALBA Synchrotron have performed the first detailed measurement of the strong metal-support interaction (SMSI) effect in Cu-Ni nanoparticles supported on cerium oxide.

A better understanding of this effect is essential for developing smart catalysts that are more selective, stable and sustainable. The quest for the best catalysts in industry has been a long one, but a new study by Universidade Federal do Rio Grande do Sul in Brazil, in collaboration with the ALBA Synchrotron, has come a step closer. For the first time, researchers have found evidence of what could be the origin of the SMSI effect in catalysts supported on cerium oxide.

Catalysts are used to increase the reaction rate of a given chemical reaction, and have applications in a wide variety of fields. In heterogeneous catalysis, the catalyst is usually composed of metal nanoparticles supported on metal oxides. Among them, CeO₂-based catalysts have unique structural and atomic properties that make them suitable in the cutting-edge environmental industry of fuel cells and hydrogen. In this field, they are being explored as high-end photocatalytic reactors for the thermal splitting of water and carbon dioxide. However, what has been termed as the SMSI effect can undermine their desired properties.

>Read more on the ALBA website

Image: (extract, full picture here) Near Ambient Pressure – X-ray Photoemission Spectroscopy allowed the identification of the chemical components of the nanoparticles in situ.

The search for clean hydrogen fuel

2018/10/192018/10/22

The world is transitioning away from fossil fuels and hydrogen is poised to be the replacement.

Two things are needed if we are to make the transition to a low carbon, “hydrogen economy” they are clean and high yielding sources of hydrogen, as well as efficient means of producing and storing energy using hydrogen.

Hydrogen powered cars are the perfect case study for how a hydrogen-fuelled future would look. While they work and show a great deal of promise, the best examples of hydrogen being used in fuel require very clean sources of hydrogen. If the source of hydrogen is mixed with contaminants like carbon monoxide, the efficiency of the fuel goes down and causes downstream problems in the fuel cell.

A team from KTH led by Jonas Weissenrieder is visiting MAX IV this week to try and solve this exact problem, how can we generate clean hydrogen for fuel cells? The team is working on a process to catalyse the oxidation of carbon monoxide, which adversely affects fuel cell performance, to harmless carbon dioxide. The catalysis reaction must be selective, and not affect the hydrogen gas that could be oxidised to water which is not great for running car engines.

Graphene-Based Catalyst Improves Peroxide Production

2018/08/222018/08/30

Hydrogen peroxide is an important commodity chemical with a growing demand in many areas, including the electronics industry, wastewater treatment, and paper recycling.

Hydrogen peroxide (H₂O₂) is a common household chemical, well known for its effectiveness at whitening and disinfecting. It’s also a valuable commodity chemical used to etch circuit boards, treat wastewater, and bleach paper and pulp—a market expected to grow as demand for recycled paper products increases.

Compared to chlorine-based bleaches, hydrogen peroxide is more environmentally benign: the only degradation product of its use is water. However, it’s currently produced through a multistep chemical reaction that consumes significant amounts of energy, generates substantial waste, and requires a catalyst of palladium—a rare and expensive metal. Furthermore, the transport and storage of bulk hydrogen peroxide can be hazardous, making local, on-demand production highly desirable.

Better living through electrochemistry

Scientists seek a way to generate hydrogen peroxide electrochemically—by a much simpler process called the oxygen reduction reaction (ORR). This reaction takes oxygen from the air and combines it with water and two electrons to produce H₂O₂. If this reaction could be efficiently catalyzed, it could enable the disinfection of water at remote locations, or during disaster recovery, using hydrogen peroxide made from local air and water. For this work, the researchers focused on hydrogen peroxide synthesis in alkaline environments, where the reaction bath can be used directly, such as for bleaching or the treatment of acidic waste streams.

Image: The production of hydrogen peroxide (H₂O₂) from oxygen (O₂) was efficiently catalyzed by graphene oxide, a form of graphene characterized by various oxygen defects that act as centers for catalytic activity. Depicted are two types of defects: one in which an oxygen atom bridges two carbon atoms above the graphene plane, and one where oxygen atoms replace carbon atoms within the graphene plane.

Demonstrating a new approach to lithium-ion batteries

2018/08/032018/08/06

A team of researchers from the University of Cambridge, Diamond Light Source and Argonne National Laboratory in the US have demonstrated a new approach that could fast-track the development of lithium-ion batteries that are both high-powered and fast-charging.

In a bid to tackle rising air pollution, the UK government has banned the sale of new diesel and petrol vehicles from 2040, and the race is on to develop high performance batteries for electric vehicles that can be charged in minutes, not hours. The rechargeable battery technology of choice is currently lithium-ion (Li-ion), and the power output and recharging time of Li-ion batteries are dependent on how ions and electrons move between the battery electrodes and electrolyte. In particular, the Li-ion diffusion rate provides a fundamental limitation to the rate at which a battery can be charged and discharged.

Scientists discover material ideal for smart photovoltaic windows

2018/01/222018/01/24

Berkeley Lab researchers make thermochromic windows with perovskite solar cell

Smart windows that are transparent when it’s dark or cool but automatically darken when the sun is too bright are increasingly popular energy-saving devices. But imagine that when the window is darkened, it simultaneously produces electricity. Such a material – a photovoltaic glass that is also reversibly thermochromic – is a green technology researchers have long worked toward, and now, scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have demonstrated a way to make it work.

Researchers at Berkeley Lab, a Department of Energy (DOE) national lab, discovered that a form of perovskite, one of the hottest materials in solar research currently due to its high conversion efficiency, works surprisingly well as a stable and photoactive semiconductor material that can be reversibly switched between a transparent state and a non-transparent state, without degrading its electronic properties.

Image Credit: iStock