In this study, we investigated the electronic properties and selective adsorption for CO₂ of nickel boride clusters (NiB)_n, (n = 1~10) using the first principles method. We optimized the structures of the clusters and analyzed their stability based on binding energy per atom. It was observed that (NiB)_n clusters adopt 3D geometries from n = 4, which were more stable compared to the plane clusters. The vertical electron affinity, vertical ionization energy, chemical potential, and highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap were calculated. Our results revealed that (NiB)₆ and (NiB)₁₀, with high chemical potential, exhibit a higher affinity for CO₂ adsorption due to a charge delivery channel that forms along the Ni→B→CO₂ path. Notably, (NiB)₁₀ demonstrated a more practical CO₂ desorption temperature, as well as a broader window for the selective adsorption of CO₂ over N₂. The density of states analysis showed that the enhanced CO₂ adsorption on (NiB)₁₀ can be attributed to the synergistic effect between Ni and B, which provides more active sites for CO₂ adsorption and promotes the electron transfer from the surface to the CO₂ molecule. Our theoretical results imply that (NiB)₁₀ should be a promising candidate for CO₂ capture.

In order to study the influence of typical coal-fired flue gas components on the supersaturation characteristics in a multisection growth tube, a two-dimensional heat and mass transfer model was used to predict the supersaturation profiles formed by the cool saturated flow into a warm-walled growth tube (Method 1) and the warm saturated flow into a cold-walled growth tube (Method 2). The calculated results show that the increase in the concentration of the three typical components CO₂, SO₂, and RH (relative humidity) of the flue gas is beneficial for the achievement of the supersaturated environment in Method 1. Additionally, having too many sections of the growth tube has a disadvantage in achieving the supersaturation profiles. When the content of the gas of lower Le is higher, having more sections of the growth tube is beneficial to achieving a supersaturated environment, while a lower number of sections is necessary when the gas content is lower in Method 2. In a word, the appropriate number of sections in a growth tube is significantly important for the achievement of a favorable supersaturated environment.