No abstract

Iron corrosion causes a great damage to the economy due to the function attenuation of iron‐based devices. However, the corrosion products can be used as active materials for some electrocatalytic reactions, such as oxygen evolution reaction (OER). Herein, the oxygen corrosion on Fe foams (FF) to synthesize effective self‐supporting electrocatalysts for OER, leading to “turning waste into treasure,” is regulated. A dual chloride aqueous system of “NaCl‐NiCl2” is employed to tailor the structures and OER properties of corrosion layers. The corrosion behaviors identify that Cl− anions serve as accelerators for oxygen corrosion, while Ni2+ cations guarantee the uniform growth of corrosion layers owing to the appeared chemical plating. The synergistic effect of “NaCl‐NiCl2” generates one of the highest OER activities that only an overpotential of 212 mV is required to achieve 100 mA cm−2 in 1.0 m KOH solution. The as‐prepared catalyst also exhibits excellent durability over 168 h (one week) at 100 mA cm−2 and promising application for overall water splitting. Specially, a large self‐supporting electrode (9 × 10 cm2) is successfully synthesized via this cost‐effective and easily scale‐up approach. By combining with corrosion science, this work provides a significant stepping stone in exploring high‐performance OER electrocatalysts.

Direct formic acid fuel cells (DFAFCs) are considered as one of the promising energy conversion devices. In recent years, Pd-based nanomaterials have attracted widespread attention for the anodic formic acid oxidation reaction (FAOR) due to high catalytic activity and antipoisoning capability. Among large amounts of reports, several factors contribute to the FAOR performance concurrently. In this review, the effects which influence the catalytic activity toward the FAOR are concluded and the deactivation mechanisms are compared. Besides, the strategies for removal/restriction of adsorbed CO species, which poison the active sites, are discussed. Several strategies, including the morphology tailoring, alloying with other elements, and optimizing the support, are presented comprehensively. Finally, we summarize these works and provide some suggestions for the future work on the FAOR catalysts.

Heteroatom doping is widely recognized as an appealing strategy to break the capacitance limitation of carbonaceous materials toward sodium storage. However, the concrete effects, especially for heteroatomic phase transformation, during the sodium storage reaction remain a confusing topic. Here, a novel hypercrosslinked polymerization approach is demonstrated to fabricate pyrrole/thiophene hypercrosslinked microporous copolymer and further give porous carbonaceous materials with accurately regulated N/S dual doping corresponding to starting feeding ratios. Significantly, the N doping contributes to the conductivity and surface wettability, while the S doping is bridged to build stable active sites, which can be electrochemically converted into mercaptan anions via faraday reaction and further enhancing reversible capacities. Meanwhile, the abundant S doping can also conduce to the expanded interlayer spacing to shorten the ions diffusion distance, thus optimizing the reaction kinetic. As a result, the N0.2S0.8‐micro‐dominant porous carbon delivers the highest reversible capacity of 521 mAh g−1 at 100 mA g−1 and excellent cyclic stability over 2000 cycles at 2000 mA g−1 with a capacity decay of 0.0145 mAh g−1 per cycle. This work is anticipated to provide an in‐depth understanding of capacitance contribution and illuminate the heteroatomic phase transformation during sodium storage reactions for doping carbonaceous anodes.

Producing high‐purity hydrogen from water electrocatalysis is essential for the flourishing hydrogen energy economy. It is of critical importance to develop low‐cost yet efficient electrocatalysts to overcome the high activation barriers during water electrocatalysis. Among the various approaches of catalyst preparation, corrosion engineering that employs the autogenous corrosion reactions to achieve electrocatalysts has emerged as a burgeoning strategy over the past few years. Benefiting from the advantages of simple synthesis, effective regulation, easy scale‐up production, and extremely low cost, corrosion engineering converts the harmful corrosion process into the useful catalyst preparation, achieving the goal of “transforming damage into benefit.” Herein, the concept of corrosion engineering, fundamental reaction mechanisms, and affecting factors are firstly introduced. Then, recent progresses on corrosion engineering for fabricating electrocatalysts toward water splitting are summarized and discussed. Specific attentions are devoted to the formation mechanisms, catalytic performances, and structure–activity relations of these catalysts as well as the approaches employed for performance improvements. At last, the current challenges and future exploiting directions are proposed for achieving highly active and durable electrocatalysts. It is envisioned to shed light on the multidisciplinary corrosion engineering that is closely associated with corrosion and material science for energy and environmental applications.