Abstract
Pursuing high energy efficiency and reaction rate is an effective direction in mitigating the energy and climate crisis. Mass transfer intensification is a powerful approach to enhance the energy efficiency and reaction rate in the energy conversion and storage processes. The nature-inspired channels are outstanding tools to uniformly distribute the reactants, fast remove products, and reduce the diffusion distance for mass transfer intensification in monolithic adsorbents, structured catalysts, and electrodes. Besides, hierarchical pores are also a contributor to improve the reactant diffusion rate in the matrix. Additive manufacturing, combining the design of printing material and post-treatment, provides a promising opportunity to accurately control the channels and adjust the pores in electrodes, catalysts, and adsorbents. This review summarizes the main state-of-the-art methods to design ideal channels and to control the sizes and amounts of pores for the optimum hierarchical structure design, as well as the techniques to realize the hierarchical structure by additive manufacturing. In addition, this review also communicates the recently unlocked advantages of the designable channels and hierarchical pores in applications of adsorptions, chemical reactions, and electrochemical energy storage. Lastly, a new approach to design and fabricate the hierarchical structures is proposed, along with its potential benefits.