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Iron porphyrins have demonstrated remarkable catalytic activity as electrocatalysts for the carbon dioxide reduction reactions (CO2RR). To enhance their catalytic activity, iron(iii) tetrakis(4-(diphenylamino)phenyl)porphyrin (FeTDPP) and iron(iii) tetrakis(carbazol-9-ylphenyl)porphyrin (FeTCPP) were synthesized by incorporating triphenylamine and phenylcarbazole substituents at the mesoposition. Both FeTDPP and FeTCPP were able to electrocatalytic reduce CO2to CO with a Faraday efficiency exceeding 90%. Compared with the benchmark catalyst, iron(iii) tetra(meso-phenyl)porphyrin (FeTPP), FeTDPP and FeTCPP exhibit lower overpotentials that are positively shifted by approximately 10 mV and 90 mV, respectively.

To expand the industrial application of cemented carbide, micro-EDM was utilized to machine microhole-textures on the carbide surface; graphite powder was burnished into the textured microholes. The tribological properties of the microhole-textured tool combined with graphite were investigated and compared with the conventional one by carrying out reciprocating sliding friction tests and dry machining tests. Results exhibited that the microhole-textured tool combined with graphite possessed a much lower friction coefficient than that of the conventional one in sliding tests. The cutting forces, average friction coefficient at the tool–chip interface, and rake face wear of the textured tool were reduced, and the workpiece surface quality was also slightly improved. The worn regions of carbide specimen were examined and studied, and the possible effect mechanisms for the enhancement of friction and wear properties mainly consisted of the formation of uneven graphite film by friction extrusion, reduction of actual contact length, entrapment of wear debris and supply of graphite lubricant.