Single-atom catalysts (SACs), particularly nitrogen-doped carbon-supported metal catalysts (M-N-C), have emerged as promising alternatives to noble metals for catalytic hydrogenation. However, their industrial application is often hindered by mass transfer limitations; active sites buried deep within tortuous porous networks remain inaccessible to bulky reactant molecules, severely limiting catalytic efficiency. While previous research has focused on increasing pore size or surface area, the impact of pore orientation on performance has remained largely unexplored.
A research team led by Prof. Liqiang Wang from Zhengzhou University has now shed light on this critical factor. In a study published in Nano Research, the team systematically investigated how pore orientation influences the hydrogenation of para-chloronitrobenzene (p-CNB) using cobalt single-atom catalysts. The researchers synthesized two types of catalysts using a hard-template method: one with oriented, straight pores (Co-SAC/OPC) derived from SBA-15, and another with non-oriented, distinct pore networks (Co-SAC/NOPC) derived from MCM-48. Despite having similar chemical compositions and single-atom dispersion, the catalyst with oriented pores exhibited a catalytic activity approximately three times higher than its non-oriented counterpart.
“Rational control of pore orientation holds great potential to enhance mass transfer in carbon-supported single-atom catalysts, thereby increasing single-atom site utilization,” said Prof. Wang. “Our results show that oriented pores facilitate diffusion more effectively, preventing the ‘traffic jams’ of molecules that occur in disordered pore networks.”
To validate their findings, the team combined experimental kinetics—such as diffusion tests and substrate size-dependent conversion analysis—with finite-element simulations using COMSOL software. The simulations visually confirmed that particles diffuse smoothly through oriented channels, whereas non-oriented structures cause significant accumulation and blockage, limiting the access to active sites. This work establishes a general strategy for enhancing the performance of carbon-supported single-atom catalysts. By optimizing pore orientation alongside traditional parameters like pore size, researchers can design more efficient and durable catalysts for hydrogenation and related reactions.
The research team includes Yangyang Fan, Jianfei Dang, Miao Jin, and Liqiang Wang from Zhengzhou University, alongside collaborators Kaiwei Liu from the Shanghai Space Propulsion Technology Research Institute and Yajing Han from the Henan University of Technology. The work was supported by the National Natural Science Foundation of China and the Excellent Young Scientists Fund of Henan Province.
Journal: Nano Research
DOI: 10.26599/NR.2026.94908540
Article Title: Shedding light on the effect of pore orientation on hydrogenation over carbon-supported single-atom catalysts
Article Publication Date: 28-May-2026
Funding: National Natural Science Foundation of China, Excellent Young Scientists Fund of Henan Province
Source: EurekAlert