Edge-substituents and center metal optimization boosting oxygen electrocatalysis in porphyrin-based covalent organic polymers.

The promising non-noble electrocatalyst with well-defined structure is significant for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for the renewable energy devices like zinc-air batteries (ZABs). Herein, the four phenyl-linked cobaltporphyrin-based covalent organic polymers (COPs-1-4) with the different edge substituents (1 = -tBu, 2 = -Me, 3 = -F, and 4 = -CF) are firstly designed and synthesized via a simple, efficient one-pot method. With the increase of electron donating capacity of the substituents, the highest occupied molecular orbital energy (E) gradually increases in the order of COP-4 < COP-3 < COP-2 < COP-1.

Low-loading Pt nanoparticles combined with the atomically dispersed FeN sites supported by Fe-N-C for improved activity and stability towards oxygen reduction reaction/hydrogen evolution reaction in acid and alkaline media.

Reducing the loading of Pt precious metal is the promising pathway to positively promote the large-scale application for fuel cells and water electrolysis. In this work, a composite bifunctional electrocatalyst (named Pt@Fe-N-C) consisting of the atomically dispersed FeN active sites and Pt nanoparticles (NPs) is successfully prepared for oxygen reduction reaction (ORR) and hydrogen evolution reactions (HER). In the process of synthesizing precursor of Pt(OH)-Fe-Ppy@CNFs, the Fe-Ppy@CNFs was firstly prepared where the highly dispersed Fe ions were pre-anchored into polypyrrole (PPy) matrixes through in-situ polymerization on the surface of cellulose nanofibers (CNFs) and then Pt(OH) nano-particles were deposited on Fe-Ppy@CNFs through adjusting the pH of the solution by urea hydrolysis to obtain the Pt(OH)-Fe-Ppy@CNFs.

High-Nuclear Organometallic Copper(I)-Alkynide Clusters: Thermochromic Near-Infrared Luminescence and Solution Stability.

Cu(CF COO) reacts with tert-butylacetylene (tBuC≡CH) in methanol in the presence of metallic copper powder to give two air-stable clusters, [Cu (tBuC≡C) (CF COO) ]⋅tBuC≡CH (1) and [Cu (tBuC≡C) (CF COO) (CH OH) ] (2). The assembly process involves in situ comproportionation reaction between Cu and Cu and the formation of two different clusters is controlled by reactants concentration. The clusters consist of Cu and Cu cores co-stabilized by strong by σ- and π-bonded tert-butylethynide and CF COO (together with methanol molecule in 2).