Recent Advances of PtCu Alloy in Electrocatalysis: Innovations and Applications

Chen S., Zhang T., Han J., Qi H., Jiao S., Hou C., Guan J.

To realize large-scale hydrogen production by electrolysis of water, it is essential to develop non-precious metal catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Here, we fabricate Sn-, Fe-, and Co-based sulfide/oxyhydroxide heterostructural catalyst on nickel foam (FeSnCo0.2SxOy/NF) by solvothermal method. The FeSnCo0.2SxOy/NF requires low overpotentials of 48 and 186 mV at 10 mA·cm–2, respectively, for HER and OER. When it is assembled into an electrolytic cell as a bifunctional electrocatalyst, it only needs 1.54 V to reach 10 mA·cm–2, far better than IrO2||Pt/C electrolyzer. The formation of sulfide/hydroxide heterostructural interfaces improves the electron transfer and reduces the reaction energy barrier, thus promoting the electrocatalytic processes.

Tang J., Xie R., Pishva P., Shen X., Zhu Y., Peng Z.

This perspective delves into electrochemically active and regenerable liquid organic hydrogen carriers (LOHCs), exploring their electrochemical properties and applications in hydrogen storage, regenerative fuel cells, batteries, and flow batteries.

Kim H., Kim D., Son J., Jang S., Chung D.Y.

Zhou M., Zhao Y., Zhao X., Yin P., Dong C., Liu H., Du X., Yang J.

Nie M., Xu Z., Wang Y., You H., Luo L., Li B., Mutahir S., Gan W., Yuan Q.

Due to the challenges involved in achieving high metal load, uniform metal dispersion and nanosized metal particles simultaneously, it is difficult to develop a simple protocol for the rapid and efficient synthesis of Pt-based composites for electrocatalytic ethanol oxidation reaction (EOR). In this study, a facile ultrafast thermal shock strategy via Joule heating was applied to fabricate a series of PtCoCu ternary nanoalloys decorated carbon nanotube composites (TS-PtCoCu/CNTs), without the need for a reducing agent or surfactant. The TS-PtCoCu/CNTs with optimal Pt content (∼15 %) exhibited excellent EOR activity, with mass and specific activity of 3.58 A mgPt−1 and 5.79 mA cm−2, respectively, which are 3.8 and 13.5 times higher than those of Pt/C. Compared with the control prepared through the traditional furnace annealing, the catalyst also showed excellent activity and stability. DFT calculations revealed that the TS-PtCoCu/CNTs possesses a downshifted d-band center, weakened CO adsorption and higher OH affinity compared with monometallic Pt, all of which lead to the preferred C1 pathway for EOR. This study demonstrates an ultrafast construction of a highly efficient Pt-Co-Cu ternary catalyst for EOR. Additionally, it provides insights into the reaction mechanism based on structural characterization, electrochemical characterization, and theoretical calculations.

Deng Z., Gong Z., Gong M., Wang X.

Zhou Y., Yuan Q.

PtCu/Pt core/atomic-layer shell hollow octahedra were fabricated as efficient and stable electrocatalysts for acidic oxygen reduction and methanol oxidation reactions.

Matsui H., Asako S., Chen C., Zhao X., Uruga T., Tada M.

The local structures and oxygen reduction performances of Pt-Cu fuel-cell electrocatalysts on robust TiN nanoparticles were investigated. The structures of the PtCu/TiN catalysts were characterized by XRF, XRD, TEM, STEM-EDS,...

An Z., Li H., Zhang X., Xia Z., Zhang H., Chu W., Yu S., Wang S., Sun G.

Wang H., Zhang K., Wu L., Wang Y., Du X., Li J.

The development of active and durable low-Pt electrocatalysts for oxygen reduction reaction (ORR) is the key target for proton exchange membrane fuel cells. Herein, a charge transfer and spillover effect enabled efficient ordered porous titanium dioxide supported PtCu alloy-based carbon-free ORR catalyst (PtCu@TiO2-xN) is developed. Experimental characterization and theoretical analysis reveal that the rich oxygen vacancies and N-doping of TiO2 support promotes the electron transfer from PtCu to TiO2-xN, resulting in electron-deficient PtCu surface. This weakens the adsorption of ORR intermediates on PtCu, and simultaneously promotes their spillover from PtCu sites to adjacent TiO2-xN support. This dynamic renewal of the PtCu active sites allows the rapid proceed of ORR, and thus accelerating its reaction kinetics. Accordingly, the PtCu@TiO2-xN catalyst exhibits greatly enhanced ORR activity with a specific activity of 1.83 mA cm−2Pt, mass activity of 1.24 A mg−1Pt and excellent durability as well. The results show that the rational design of Pt-based catalyst with spillover effect is of great significance towards efficient ORR reaction.

Xiao L., Qi L., Sun J., Husile A., Zhang S., Wang Z., Guan J.

Covalent organic frameworks (COFs) have become the most attractive frontier research field in heterogeneous catalysis. Since the geometric and electronic structures of COFs depend greatly on their microenvironment, which, in turn, determine the performances in electrocatalytic processes, the precise integration of atoms of building blocks of COFs to achieve pre-designed compositions, components and functions is the core. In this review, we focus on the latest progress in the structural design, synthesis, characterizations and applications of COFs, with emphasis on electrocatalytic mechanisms. Furthermore, we have proposed a variety of optimizing strategies including structural regulation (including building unit, linkage, and topological structure), pore surface engineering, side chain modification engineering, regulating non-metallic sites, regulating metal sites, regulating single metal active sites, defect engineering, and regulating composite materials to improve the electrocatalytic intrinsic activities of COFs. Experimental and theoretical advances in understanding such microenvironment in association to the electrocatalytic activity and mechanisms are exemplified in the electrochemical applications, including H2/O2 evolution reactions and O2/CO2 reduction reactions. Finally, by highlighting the prospects and challenges for structural regulations of COFs, we wish to shed some light on the further development of COFs for electrocatalysis applications.

Bayat R., El Attar A., Akin M., Bekmezci M., El Rhazi M., Sen F.

The design of efficient, durable and inexpensive electrocatalysts is of great importance in the development of direct alcohol fuel cells, a clean energy source. In this context, in this study, chain-like platinum-copper (PtCu) nanoparticles were synthesised by chemical reduction method to be used in alcohol oxidation studies. X-Ray diffraction analysis (XRD) of the synthesised nanoparticles showed the formation of PtCu crystal structure. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) analysis showed the formation of chain-like PtCu structures and particles with an average size of 4.04 nm. These PtCu nanocomposite structures were used in electro oxidation studies of ethanol, methanol and 2-propanol. As a result of the oxidation studies, anodic peak currents of 253.1 mA cm−2, 187.7 mA cm−2, 37.2 mA cm−2 were obtained for methanol, ethanol and 2-propanol, respectively. It was also observed that PtCu has a higher electrochemically active surface area than bare Pt and is more tolerant to CO. The results showed that the synthesised catalyst showed very high electrocatalytic activity and stability in alcohol fuel cells. With this study, important results have been given for the stability problem, which is one of the biggest problems in fuel cells.

Chen Y., Wu Y., Chang Y., Yang Z., Song X., Zhou W., Wang J., Li H.

Designing highly efficient and durable electrode for methanol oxidation reaction (MOR) is crucial to commercializing direct methanol fuel cells (DMFCs). However, traditional Pt/C catalysts usually suffer from CO poisoning, and agglomeration of powder catalyst, which leads to rapid activity degradation. Herein, we have successfully fabricated self-supported Pt3Cu@3DP-WO3/W electrode via a facile and effective synthesis approach by combining anodic oxidation and electrodeposition method. Benefitting from the three dimensional nanoporous of WO3 with more surface area and strong adhesion, and Pt3Cu alloy synergism induced the lattice compressive strain, the Pt3Cu@3DP-WO3/W electrode achieved 2.77-fold and 4.8-fold enhancement in specific activity (2.15 mA cm−2) and mass activity (853 mA·mgPt−1) for MOR relative to Pt/C catalysts, respectively. Moreover, both the experiments and theoretical calculations revealed that the doping of Cu element weakened the chemisorption of CO-like intermediates by lowering the Pt d-band center through compressive lattice strain, which resulting in excellent catalytic stability. This binder-free self-supported electrode is a viable alternative for commercial application of DMFCs.

Zou T., Wang Y., Xu F.

Sun Y., Zhang S., Sun S., Wu L., Tian J., Wu Y., Chen Y., Liu X.

AbstractSurface engineering offers opportunities for the design and synthesis of Pt‐based alloyed electrocatalysts with high mass activity and resistance to CO poisoning, which is of great significance for methanol electrooxidation. Surface curvature regulation may endow electrocatalysts with enhanced atomic utilization and abundance of unsaturated atoms; however, a reliable synthetic route for controlled construction of tailorable curved surface is still lacking. Here, a colloidal‐chemical method to synthesize two types of PtCu branched‐structured electrocatalysts, where the concave curvature can be customized is reported. These studies show that, among various synthesis parameters, the concentration of CuCl2·2H2O precursor is the key factor in manipulating the reaction kinetics and determining the concave surface curvature. Significantly, PtCu branched nanocrystals with long and sharp arms (PtCu BNCs‐L), featuring a high concave surface curvature, exhibit remarkable activity and stability toward MOR, which is mainly attributed to advanced features of a highly concave surface and the synergistically bifunctional effect from introduced oxophilic Cu metal. In situ Raman spectroscopy and CO stripping test demonstrates weakened CO adsorption and accelerated CO removal on PtCu BNCs‐L. This work highlights the importance of surface curvature, opening up an appealing route for the design and synthesis of advanced electrocatalysts with well‐defined surface configurations.

Ren F., Lv T., Wang C., Du Y.

Alekseenko A.A., Paperzh K.O., Pavlets A.S., Belenov S.V., Moguchikh E.A., Nevelskaya A.K., Bayan Y.A., Danilenko M.V., Pankov I.V., Guterman V.E.

Tang J., Li J., Wu D., Xie R., Peng Z.