Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction

Abstract

The development of an efficient catalyst system for the electrochemical reduction of carbon dioxide into energy-rich products is a major research topic. Here we report the catalytic ability of polyacrylonitrile-based heteroatomic carbon nanofibres for carbon dioxide reduction into carbon monoxide, via a metal-free, renewable and cost-effective route. The carbon nanofibre catalyst exhibits negligible overpotential (0.17 V) for carbon dioxide reduction and more than an order of magnitude higher current density compared with the silver catalyst under similar experimental conditions. The carbon dioxide reduction ability of carbon nanofibres is attributed to the reduced carbons rather than to electronegative nitrogen atoms. The superior performance is credited to the nanofibrillar structure and high binding energy of key intermediates to the carbon nanofibre surfaces. The finding may lead to a new generation of metal-free and non-precious catalysts with much greater efficiency than the existing noble metal catalysts.

Zinc Imidazolate Metal–Organic Frameworks (ZIF‐8) for Electrochemical Reduction of CO2 to CO

“…[1][2][3] Electrochemical reduction of CO 2 ,u sing electricity from renewable resources, is ap otentially "clean"s trategy to obtain fuels and chemicals under mild conditions. [4][5][6][7][8] However, efficient and robust catalysts operatinga ts mall over-potentials with high selectivity and efficiency are still required for technology commercialization.…”

Carbon-Based Metal-Free Electrocatalysis for Energy Conversion, Energy Storage, and Environmental Protection

“…11, metal-free carbon catalysts based on N-doped carbon nanofibers (NCNFs) generated from the electrospinning of polyacrylonitrile (PAN) was first reported in 2013 for CO 2 RR [36]. Subsequently, N-doped CNTs (NCNTs) were demonstrated to be highly active, selective, and stable catalysts for the electrocatalytic reduction of CO 2 to CO [37][38][39][40].…”

“…In this context, carbon-based metal-free catalysts have also been used for CO 2 RR. Figure 11 and Table 1 represent recent advances in the development of carbon-based metal-free catalysts for CO 2 RR [36,37,[207][208][209][210][211][212][213][214].…”

“…Because of high abundance, high electrical conductivity, structure tunability at the atomic level, high selectivity, strong tolerance to acidic/alkaline conditions, and eco-friendliness [4,5], many nanostructured carbon materials have been developed as metal-free catalysts with impressive electrocatalytic performances for ORR, HER, OER, and/or CO 2 RR, key reactions involved in energy conversion/storage and environmental protection processes [3,[6][7][8][9]. The electrocatalytic performances of metal-free carbon-based catalysts were further found to be tuneable through the regulation of the nanoparticles size, macrostructures, and electrode architectures, along with the introduction of heteroatoms (doping) and defects [8,9].…”

“…Because ORR, OER, and HER have been reviewed in several previously published articles [4,[10][11][12], the focus in this review will be on recent advances and new reactions (e.g., CO 2 RR, multifunctional electrocatalysis). A critical overview of efficient methods for developing carbon-based metal-free catalysts for various energy conversion/storage and environmental protection devices, including ORR in fuel cells [13][14][15][16][17], ORR and OER in metal-air batteries [18][19][20][21][22][23][24][25][26][27][28], OER and HER in water-splitting units [29][30][31], I − /I 3− reduction in dye-sensitized solar cells [32][33][34][35], and CO 2 RR in Li-CO 2 batteries [36][37][38][39][40][41][42] will then be provided. Finally, perspectives and challenges in this fast-growing and significant field are outlined.…”