How sunlight and CO2 can be turned into sustainable fuel
In a recent article published in the journal Sustainable Energy & Fuels, researchers present a new process that uses sunlight to convert CO2 into methanol. This methanol can be used as a sustainable fuel. This sounds promising, but is it too early to be jubilant?
The process described in the study is based on photocatalysis. In this process, sunlight is used to initiate chemical reactions. The researchers developed a material made of copper atoms bonded to nanocrystalline carbon nitride. The electrons of the carbon nitride are activated by sunlight and can move freely. These electrons then move in the direction of CO2 and thus enable the conversion of CO2 into methanol. The copper atoms act as a catalyser.
But how does this process differ from previous methods? According to the researchers, there are two main things: efficiency and selectivity. Conventional methods for converting CO2 into usable products were neither particularly efficient nor selective. With the new material and copper atoms as a catalyst, the researchers can control the reaction in such a way that mainly methanol and fewer by-products are produced.
Another advantage is the utilisation of renewable energy sources. Instead of fossil fuels, the process relies on sunlight. So is this a sustainable, environmentally friendly approach to producing fuels and other chemical compounds from CO2?
Although the researchers emphasise that their process is more efficient and selective than conventional methods, there is a lack of concrete figures and data to back up these claims. How exactly is this "efficiency" defined? And how high is the actual yield of methanol compared to other by-products? The production of the material from copper atoms and nanocrystalline carbon nitride itself requires resources and energy. Is it really sustainable if you look at the entire production chain?