Ethylene electrosynthesis from low-concentrated acetylene via concave-surface enriched reactant and improved mass...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic semihydrogenation of acetylene (C2H2) offers a sustainable route to ethylene (C2H4) production, independent of petroleum resources.
• Current methods are economically limited by the need for pre-separation and concentration of raw coal-derived C2H2.
• Enriching C2H2 and optimizing mass transfer kinetics are crucial for direct conversion of raw C2H2.

Purpose of the Study:

• To design an electrode that enriches acetylene (C2H2) and optimizes its mass transfer kinetics for direct conversion.
• To investigate the performance of a porous concave carbon-supported Cu nanoparticle (Cu-PCC) electrode for electrocatalytic semihydrogenation of raw coal-derived C2H2.
• To understand the mechanism behind enhanced ethylene (C2H4) selectivity and conversion.

Main Methods:

• Computational prediction of concave surface benefits for C2H2 enrichment and mass transfer.
• Fabrication of a porous concave carbon-supported Cu nanoparticle (Cu-PCC) electrode.
• Electrocatalytic testing under a simulated raw coal-derived C2H2 atmosphere (~15%) at a partial current density of 0.42 A cm⁻².

Main Results:

• The Cu-PCC electrode achieved 91.7% C2H4 Faradaic efficiency and 56.31% C2H2 single-pass conversion.
• Performance significantly surpassed electrodes without concave surface supports.
• Increased C2H2 coverage on the concave surface strengthened π conjugation, promoting C2H2 activation and C2H4 selectivity while suppressing hydrogen evolution.

Conclusions:

• Porous concave carbon supports are effective in enriching C2H2 and enhancing electrocatalytic semihydrogenation.
• The developed Cu-PCC electrode enables efficient direct conversion of raw coal-derived C2H2 to C2H4.
• The study elucidates the mechanism of enhanced selectivity through strengthened π conjugation and electron delocalization.