Reduce CO2 emissions of roads, railways and shipping requires the simultaneous implementation of a series of solutions. With regard to cars, reducing the number of journeys (by making it easier for people to walk and cycling and improving public transport), changing fuel in vehicles and making the most of the vehicles already on the road should away, all play an important role. part.
None of these solutions is sufficient on its own.
By 2030, the sale of new diesel and petrol passenger cars will be banned in the UK. The future of passenger cars will be electric. But recent parts supply problems and the high carbon costs of electric vehicle production could delay the climate benefits of this transition.
To make the most of existing petrol and diesel cars — and the carbon invested to make them — motorists and manufacturers can reduce emissions of a family of compounds called nitrogen oxides, which are linked to respiratory diseases, by better treatment of exhaust gases. In this way, the communities most affected by air pollution can at least be protected before the harmful emissions from vehicles are permanently eradicated.
My research team is developing a new generation of catalytic converters – the devices that are mounted on exhaust pipes to reduce the release of toxic gases. Inspired by chemistry observed on the surfaces of extremely hot planets such as Venus, we have produced a synthetic material that could improve air quality.
From Venus to vehicle exhausts
The light from the sun destroys carbon dioxide (CO₂) in the atmospheres of planets, producing carbon monoxide (CO). Not fast enough to avert climate change, but enough that atmospheres like Venus contain much more CO than we observe there.
Our group studies the effects of meteoric material (dust from space) in atmospheres. An iron silicate powder made by us that mimics this dust can accelerate the conversion of CO to CO₂. This is what the first catalytic converters in cars were designed for, as CO is a poisonous gas.
That got us thinking about whether this material could help with other problems, such as nitrogen oxide pollution, which exceeds the legal limits in the air of many UK cities. Poor air quality due to vehicle exhaust gases costs tens of thousands of lives every year.
We found that the powder can not only clean up CO and nitrogen oxide emissions at the same time, but it can also convert nitrogen dioxide (NO₂, a harmful gas that is specifically regulated) into harmless molecular nitrogen (N₂) and water at room temperature.
Catalysts for processing nitrogen oxide (NOx) emissions installed in modern diesel vehicles only operate at exhaust temperatures above 150°C. Even if your car uses an additive fluid to reduce nitrogen oxide emissions, it is unlikely to work while you drive slowly when the exhaust is cooler. This is when vehicles emit the most NO₂ — often in traffic jams where the most polluted air can accumulate.
When the electrical grid is low-carbon and robust enough to charge millions of electric vehicles, catalysts that can remove nitrogen oxides could still be important. For example, the natural gas fuel in industrial furnaces is likely to be replaced by hydrogen.
Unlike buses and cars that run on hydrogen, which produce energy through a reaction in a fuel cell, larger applications such as furnaces in steel mills will burn hydrogen fuel directly. This high temperature combustion converts molecular nitrogen in the air into nitrogen oxide pollution, which must be removed.
Therefore, we are excited to develop a prototype emissions converter that can work in most situations, with the potential to radically reduce toxic emissions from internal combustion engines and other sources in the future.
This article was originally published on The conversation by Alexander James at the University of Leeds. Read the original article here.