Challenges in developing direct carbon fuel cells

Abstract

A direct carbon fuel cell (DCFC) can produce electricity with both superior electrical efficiency and fuel utilisation compared to all other types of fuel cells. Although the first DCFC prototype was proposed in 1896, there was, until the 1970s, little sustained effort to investigate further, because of technology development issues. Interest in DCFCs has recently been reinvigorated as a possible method of replacing conventional coal-fired power plants to meet the demands for lower CO emissions, and indeed for efficient utilisation of waste derived chars. In this article, recent developments in direct carbon conversion are reviewed, with the principal emphasis on the materials involved. The development of electrolytes, anodes and cathodes as well as fuel sources is examined. The activity and chemical stability of the anode materials are a critical concern addressed in the development of new materials. Redox media of molten carbonate or molten metal facilitating the transportation of ions offer promising possibilities for carbon oxidation. The suitability of different carbon fuels in various DCFC systems, in terms of crystal structure, surface properties, impurities and particle size, is also discussed. We explore the influence of a variety of parameters on the electrochemical performance of DCFCs, with regard to their open circuit voltage, power output and lifetime. The challenges faced in developing DCFCs are summarised, and potential prospects of the system are outlined.

Constrained-volume assembly of organometal confined in polymer to fabricate multi-heteroatom doped carbon for oxygen reduction reaction

“…As shown in Fig. 3b, c, FNP-3 and FNP-1 from lower (Ph 3 P) 2 Fe-(CO) 3 feed concentrations retain a good dispersion of Febased NPs while the size decreases to 15 and 5 nm, respectively. Meanwhile, a sparser distribution of Fe 3 C NPs within the carbon support is observed when lowering the (Ph 3 P) 2 Fe(CO) 3 feed concentration in stream 1, indicating the ability to tune the metal NPs arrangement by changing process conditions.…”

“…The two input streams were expelled from both syringes with the same rate (~37 mL s ), causing two streams to merge and drop into a beaker filled with 20 mL H 2 O. (Ph 3 P) 2 Fe-(CO) 3 @PS-c-PAN NPs were collected by centrifugation and then dried at 60°C. Then the dried NPs were placed in a tube furnace and stabilized at 280°C for 1 h in air with heating rate of 5°C min −1 and carbonized at 800°C for 2 h under N 2 flow with a heating rate of 5°C min −1 .…”

“…Owing to the high power density and energy-conversion efficiency, fuel cells have been regarded as one of the most promising and available energy conversion technologies with nearly no environmental contamination [1,2]. Currently, Pt based nanomaterials are considered to be the most efficient electrocatalyst for cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) [3,4].…”

“…An in-situ encapsulation method would avoid the tedious steps of post-modification as well as facilitate the uniform dispersion of metallic NPs within the framework of CNFs. For example, Huang and coworkers [25] have directly electrospun a mixture of PAN and Pd(acetate) 2 , followed by carbonization. The obtained Pd/CNF composites exhibited good performance towards the reduction of H 2 O 2 and the oxidation of nicotinamide adenine dinucleotide (NADH).…”

Enhancing the Power Output of Direct Carbon Solid Oxide Fuel Cell Using Ba‐Loaded Activated Carbon Fuel

“…For this reason, many new energy devices have been developed. Among them, direct carbon fuel cell (DCFC), which converts the chemical energy of carbon to electrical power with high theoretical efficiency and high fuel utilization, received wide attention and been regarded as a promising power generation technology in the consumption of solid carbon fuels …”