Magnetic decoupling in the triangular-lattice antiferromagnet Cu2(OH)3CHO2 studied by high-field magnetization and ESR

•The magnetic decoupling between the Cu1 ferromagnetic chain and the Cu2 antiferromagnetic chain has been revealed.•The high-field magnetization presents a metamagnetic transition at 1.7 T and a half-saturated ferromagnetic (FM)-like magnetization process.•The antiferromagnetic resonances of the antiferromagnetically coupled Cu1 FM chains were observed, showing the presence of significant magnetic anisotropy.