Application-oriented non-thermal plasma in chemical reaction engineering: A review

Non-thermal plasma as a tool in chemical reaction engineering has been studied for many years. The temperature of electrons in non-thermal plasma far exceeds other particles, which leads to its high efficiency. Besides the well-studied destruction of volatile organic compounds (VOCs), the reaction environment generated by non-thermal plasma is also suitable for the activation of many significant gas-phase chemical reactions, e.g., as methane coupling, reduction of carbon dioxide, ammonia synthesis, nitrogen fixation, as well as some liquid phase chemical reactions such as the treatment of contaminated water. Material synthesis is another target field of non-thermal plasma. Plasma in micro scale with several enhanced properties makes it an even more promising tool for plasma-chemical processing. This work summarizes different types of non-thermal plasmas and their performance in commonly studied chemical reactions. The advantages gained by generating non-thermal plasma in micro scale with constricted spaces, reduced timescales, and micro-/nano-structured electrodes are also discussed. [Display omitted] •Non-thermal plasma is suitable for activating many chemical reactions because of its high efficiency and stability.•Various reactions activated by non-thermal plasma are summarized, especially the energy-consuming ones.•Better control of the energetic electrons can benefit the performance of the non-thermal plasma.•Microplasma, multiple discharges, and suitable electrode materials and structures are analyzed for their improvements in the control of energetic electrons and challenges towards industrialization.•Non-thermal plasma is a promising tool in chemical reaction engineering, especially in the background of global carbon emissions reduction.