Triboelectric Plasma CO 2 Reduction Reaching a Mechanical Energy Conversion Efficiency of 2.3.

Mechanical energy-induced CO 2 reduction is a promising strategy for reducing greenhouse gas emissions and simultaneously harvesting mechanical energy. Unfortunately, the low energy conversion efficiency is still an open challenge. Here, multiple-pulse, flow-type triboelectric plasma with dual functions of harvesting mechanical energy and driving chemical reactions is introduced to efficiently reduce CO 2 . CO selectivity of 92.4% is achieved under normal temperature and pressure, and the CO and O 2 evolution rates reach 12.4 and 6.7 µmol h -1 , respectively. The maximum energy conversion efficiencies of 2.3% from mechanical to chemical energy and 31.9% from electrical to chemical energy are reached. The low average electron energy in triboelectric plasma and vibrational excitation dissociation of CO 2 with low barrier is revealed by optical emission spectra and plasma simulations, which enable the high energy conversion efficiency. The approach of triboelectric plasma reduction reported here provides a promising strategy for efficient utilization of renewable and dispersed mechanical energy.