Deqiang Ji

Effect of molten carbonate composition on the generation of carbon material

Carbon dioxide, CO2, is thought to be a main culprit leading to global climate change and a wide variety of strategies have been proposed to reduce atmospheric CO2 levels. Here, CO2 is captured and subsequently electrochemically split into carbon materials in an electrolyzer comprising a eutectic mixture of carbonates, an Fe cathode and a Ni anode, at 600 °C and current densities of 50, 100, 200 mA cm−2. SEM, EDS, XRD and BET are employed to analyze the morphology, elemental composition, crystal structure as well as the BET surface area of the synthetic cathodic products. In addition, coulomb efficiency under different electrolytic conditions is measured via the comparison between moles of formed carbon product and the Faradays of charge passed during the electrolysis reaction. This paper investigated the effect of molten carbonate compositions on carbon product generation, and confirmed the visible dependence of produced carbon on the electrolytes.

Effect of BaCO3 addition on the CO2-derived carbon deposition in molten carbonates electrolyzer

Electrolysis of molten carbonates provides an effective means to achieve the direct conversion of the greenhouse gas carbon dioxide to readily available carbonaceous fuel or chemicals. In this study, CO2 was electrolyzed in a Li–Na–K ternary carbonates mixture using galvanized Fe as the cathode and nickel as the anode. In particular, the effect of BaCO3 on the generation of carbon was studied. The results demonstrate that BaCO3 addition facilitates the deposition of compact carbon materials. Moreover, decreasing the temperature and increasing the current density lead to the formation of loosened carbon products. Though Li–Na–K–Ba electrolysis exhibits a higher cell voltage than that using Li–Na–K carbonates, BaCO3 addition can significantly ease anode corrosion and the corresponding corrosion inhibiting action is discussed. In summary, a facile CO2 absorption and a mitigatory nickel anode corrosion were observed when BaCO3 was dissolved in Li–Na–K carbonates and further investigation is expected.

Syngas production: diverse H2/CO range by regulating carbonates electrolyte composition from CO2/H2O via co-electrolysis in eutectic molten salts

We present a novel sustainable method for the direct production of syngas (H2 + CO) from CO2/H2O co-electrolysis using a hermetic device, to address the continuously increasing level of environmental carbon dioxide (CO2). All experiments were conducted using a two-electrode system with a coiled Fe cathode and coiled Ni anode in eutectic mixtures of binary and ternary carbonates with hydroxide in a 0.1u2006:u20061 hydroxide/carbonate ratio. With an applied voltage of 1.6–2.6 V and an operating temperature of 500–600 °C, the H2/CO product ratio was easily tuned from 0.53 to 8.08 through renewable cycling of CO2 and H2O. The Li0.85Na0.61K0.54CO3–0.1LiOH composite had the highest current efficiency among those tested, with an optimum value approaching ∼93%. This study provides a promising technique for the electrochemical conversion of CO2/H2O to a controllable syngas feedstock that can be used in a broad range of industrial applications.