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Study the adsorption and reactivity of CO2 on surfaces are of great interest in technological application and fundamental sciences. Moreover, CO2 reduction into more valuable compound has been also the most effective strategy to reduce the green house effect in the atmosphere. Nowadays, graphene has been proposed as a support of catalytic materials to adsorb and reduce CO and CO2. Graphene becomes more reactive when we introduce transition metal as an adatom or dopant.[1,2] In this research, we focus on elucidating the adsorption of CO2 on pristine graphene, and graphene with Ni adatom and dopant. We performed density functional theory (DFT) study of CO2 adsorption on graphene with and without Ni adatom/dopant. We implemented van der Waals (vdW) interaction correction to accommodate weakly interaction between CO2 and graphene. In addition to those, we also compared our results with general PBE calculations. Based on vdW functional calculations, we obtained that CO2 is physisorbed on pristine graphene with adsorption energy of 0.17 eV. Meanwhile, PBE shows almost repulsive interaction between CO2 and graphene. These results are in good agreement with previous works.[3] Single Ni adatom/dopant and small Ni cluster increase the activity of graphene. We obtained that CO2 is more stable on graphene with Ni adatom rather than with Ni dopant. It turns out that Ni adatom is more reactive than Ni dopant. We noticed that Ni adatom and dopant have different local properties of electronic d states. The difference in local d state may cause variations in reactivity.[4,5] The adsorption energy further increases when we introduced small Ni cluster on graphene. The adsorbed CO2 bond angle on graphene with Ni adatom/dopant and small cluster is distorted from its gas phase condition of 180°, indicating that CO2 is chemisorbed on the decorated graphene area. Our results then provide useful insight into appropriate design of graphene supported metal catalysts. References: [1] X. Liu, Y. Sui, T. Duan, C. Meng, and Y. Han, Phys. Chem. Chem. Phys. 16, 23584-23593 (2016). [2] H. Xu, W. Chu, W. Sun, C. Jiang, and Z. Liu, RSC Adv. 6, 96545-96553 (2016). [3] K. Takeuchi, S. Yamamoto, Y. Hamamoto, Y. Shiozawa, K. Tashima, H. Fukidome, T. Koitaya, K. Mukai, S. Yoshimoto, M. Suemitsu, Y. Morikawa, J. Yoshinobu, and I. Matsuda, J. Phys. Chem. C 121, 2807 (2017). [4] B. Hammer, Y. Morikawa, and J. K. Nørskov, Phys. Rev. Lett. 76, 2141-2144 (1996). [5] B. Hammer, Surf. Sci. 459, 323-348 (2000).