CO2-assisted formation of grain boundaries for efficient CO–CO coupling on a derived Cu catalystZhuang-Zhuang Niu, Li-Ping Chi, Zhi-Zheng Wu, Peng-Peng Yang, Ming-Hui Fan and Min-Rui GaoNatl Sci Open, 2 2 (2023) 20220044DOI: https://doi.org/10.1360/nso/20220044