Ting He

The oversupply of ethane, a major component of natural gas liquids, has stimulated the wide applications of ethylene since the shale gas revolution. However, ethylene production is energy-intensive and represents the most energy-consuming single process in the chemical industry. In this communication, we report, for the first time, a novel low-thermal-budget process for the co-production of ethylene and pure hydrogen using a proton-conducting electrochemical deprotonation cell. At a constant current density of 1 A cm⁻², corresponding to a hydrogen production rate of 0.448 mol cm⁻² per day, and 400 °C, a close to 100% ethylene selectivity was achieved under an electrochemical overpotential of 140 mV. Compared to an industrial ethane steam cracker, the electrochemical deprotonation process can achieve a 65% saving in process energy and reduce the carbon footprint by as much as 72% or even more if renewable electricity and heat are used. If the heating value of produced hydrogen is taken into account, the electrochemical deprotonation process actually has a net gain in processing energy. The electrochemical deprotonation process at reduced temperatures in the present study provides a disruptive approach for petrochemical manufacturing, shifting the paradigm from thermal chemical practice to a clean energy regime.

Direct carbon fuel cells (DCFCs) are highly efficient power generators fueled by abundant and cheap solid carbons. However, the limited triple‐phase boundaries (TPBs) in the fuel electrode, due to the lack of direct contact among carbon, electrode, and electrolyte, inhibit the performance and result in poor fuel utilization. To address the challenges of low carbon oxidation activity and low carbon utilization, a highly efficient, 3D solid‐state architected anode is developed to enhance the performance of DCFCs below 600 °C. The cell with the 3D textile anode framework, Gd:CeO₂–Li/Na₂CO₃ composite electrolyte, and Sm_0.5Sr_0.5CoO₃ cathode demonstrates excellent performance with maximum power densities of 143, 196, and 325 mW cm⁻² at 500, 550, and 600 °C, respectively. At 500 °C, the cells can be operated steadily with a rated power density of ≈0.13 W cm⁻² at a constant current density of 0.15 A cm⁻² with a carbon utilization over 85.5%. These results, for the first time, demonstrate the feasibility of directly electrochemical oxidation of solid carbon at 500–600 °C, representing a promising strategy in developing high‐performing fuel cells and other electrochemical systems via the integration of 3D architected electrodes.

The presence of Ga promotes H ₂ dissociation adsorption, and subsequently improves the process of CO ₂ hydrogenation to CH ₃ OH.

Carbon nanofibers (CNFs) have wide applications in various high-tech areas.

Doped ceria has been widely studied as electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). While high peak power densities have been reported, the electronic conductivity of doped ceria under fuel cell operating conditions reduces the open circuit voltage (OCV) and hence energy efficiency, more so with thinner electrolyte membrane at higher operating temperatures. Here we report a new cell structure: a thin SDC electrolyte membrane supported by a composite anode consisting of a mixed-ion conductor BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3−δ (BZCYYb) and NiO. The inter-diffusion between BZCYYb and SDC during co-firing results in a thin layer of doped barium cerate and zirconate at the interface, which suppresses the electronic conduction of SDC and enhances the OCV and cell performance. The new cell structure also shows excellent stability when wet hydrogen or methane was used as fuel at 750°C.

The catalytic oxygen electroreduction properties of PtTiMe (Me = Co, Cr, Cu, Fe, Mn, Mo, Ni, Pd, Ta, V, W and Zr) ternary alloys were studied using an in-house developed thin film based combinatorial high throughput method. Libraries containing discrete alloy compositions were fabricated by plasma co-sputtering and the resulting alloys were electrochemically screened by the hydrodynamic rotating disk electrode technique. Candidate catalysts were identified by comparing the activity–stability–composition relationships between the platinum titanium alloys and pure platinum standard. Among the PtTiMe alloys studied, PtTiNi, PtTiCu and PtTiV, respectively, displayed the highest catalytic oxygen electroreduction activities with a tenfold, an eightfold and a sixfold enhancement as compared to the pure platinum standard and good chemical stabilities.

In situ electrochemical scanning tunneling microscopy was used to study the coarsening of platinum nanocrystals under potentiostating and the dissolution and coarsening of platinum nanocrystals through potential cycling. A rapid coarsening of platinum nanocrystals was observed for potentiostating in the double-layer region. No obvious crystal size changes were observed for potentiostating in the platinum oxidation-reduction region and the hydrogen-adsorption proton-oxidation region. The coarsening is proposed as a variant of Ostwald ripening, whereby the dominant process is potential-induced surface-diffusion transport. Additionally, potential cycling causes not only surface platinum dissolution as a result of the platinum redox reaction, but also platinum nanocrystal coarsening. Details of the platinum nanocrystal restructuring are described, and the possible influences of these phenomena on fuel cell operation are discussed.