Electrocatalysis performs an important function in creating clear power, greenhouse gasoline removing and power storage applied sciences. A research co-led by Metropolis College of Hong Kong (CityU) researchers discovered that single-walled carbon nanotubes are glorious substrates for enhancing greenhouse gasoline conversion by means of molecular curvature.

Through the use of these nanotubes as help to induce pressure on an electrocatalyst, the effectivity of carbon dioxide discount to methanol could be considerably improved.

This breakthrough opens avenues for creating curved molecular electrocatalysts to effectively convert carbon dioxide (CO₂), one of many key greenhouse gases, into helpful chemical compounds and fuels, thus decreasing carbon emission. The work is revealed within the journal Nature Catalysis.

Many molecular complexes, like cobalt phthalocyanine (CoPc), are environment friendly catalysts for CO₂ discount response (CO₂RR). Nonetheless, they primarily scale back CO₂ to toxic carbon monoxide (CO), with out additional producing a considerable quantity of helpful merchandise, like methanol. “Due to this fact, we wish to discover the potential of CoPc past CO manufacturing,” stated Professor Ye Ruquan, of the Division of Chemistry at Metropolis College of Hong Kong (CityU), who led the analysis.

On the identical time, pressure is thought to have an effect on the properties of two-dimensional supplies, which are sometimes on the scale of nanometers (nm). “Using curved substrates, or helps, to induce native pressure is effectively established for modulating the properties of standard layered supplies,” defined Professor Ye.

“However rational management of the pressure of planar molecules is difficult as a result of their ultra-small dimension. And the way the pressure impacts molecular properties stays poorly understood.”

Collectively along with his collaborators, Professor Ye led a analysis workforce to research the reactivity for molecular CoPc catalysts on the nanometer scale by adopting support-induced pressure engineering. They efficiently launched controlled-strain into sub-2 nm molecules of the catalyst by utilizing single-walled carbon nanotubes because the help.

The curvature of the nanotubes as a result of molecular interactions induces pressure on the catalytic molecules, leading to bending. Utilizing carbon nanotubes substrates with totally different diameters permits them to tune the bending angle of CoPc molecules starting from 96° (for 1-nm-diameter carbon nanotubes) to 1.5° (for 100-nm-diameter carbon nanotubes).

In contrast with conventional planar molecules, the curved molecules exhibited improved electrocatalytic efficiency. They confirmed increased selectivity for CO₂ discount, favoring the manufacturing of methanol over carbon monoxide.

In a tandem-flow electrolyzer with monodispersed CoPc on single-walled carbon nanotubes for CO₂ discount, the workforce achieved a methanol partial present density of greater than 90 mA cm⁻² with greater than 60% selectivity, that means that the full CO₂-to-methanol effectivity is 60%. It is a vital enchancment over current strategies.

Their evaluation based mostly on theoretical calculations confirmed that the curved CoPc on the single-walled carbon nanotubes enhanced CO binding, enabling the ensuing discount of carbon monoxide. In distinction, vast multi-walled carbon nanotubes favor the discharge of CO.

“Our findings present that carbon nanotubes are distinctive help supplies for catalysts like CoPc. The big particular floor areas of carbon nanotubes readily disperse nanoparticles, avoiding agglomeration, and their excessive digital conductivity make them promising for electrochemical purposes,” stated Professor Ye.

“Extra importantly, we confirmed that inducing molecular distortion by means of single-walled carbon nanotubes supplies a method for designing high-performance molecular electrocatalysts. This development holds promise for attaining carbon neutrality, as it might retailer CO₂ and renewable electrical energy as chemical power,” he concluded.