Nature has achieved materials with features and properties that surpass the current knowledge of the materials engineering, consequently, it has become a source of inspiration for innovation in high-performance porous materials, including biomorphic ceramics. These novel ceramics can be manufactured from renewable resources and exhibit a wide range of microstructures that imitate the anatomy of natural tissues, such as wood and bone, among others. The hierarchical porosity and evolutionary optimization observed in these structures offer unique microstructure-properties relationships, making them significant focal points in materials science. In particular, the wood is an excellent biotemplate, which exhibits a high degree of organization associated with a specific and homogeneous structure of interconnected open cells. The complexity of its porous structure across different scales and their unique morphology allows the development of new micro-, meso-, and macroporous ceramic structures. Thus, wood-derived ceramics are promising porous materials with a unique combination of properties, adequate for various applications in energy and catalyst, among others.

In this study, the development and characterization of biomorphic porous ceramics obtained through the infiltration of a liquid Si-based preceramic polymer (silsesquioxane synthetized by the sol-gel method) into activated poplar wood templates, thermal curing (135°C, 3h) and N2 pyrolysis (1000-1600°C, 4h) was addressed. Activated templates were characterized by porosity measurements, SEM and Hg-porosimetry. The infiltration agent was characterized by density measurements, ATR-FTIR, 1H/29Si NMR, and rheological testing. Infiltrated and cured samples were characterized via density, open porosity and mass gain measurements, and SEM. Si-based phases developed by pyrolysis were studied using XRD, TGA-mass spectrometry, and SEM/EDS. The free carbon was characterized by Raman spectroscopy. Porous microstructures were analyzed by SEM/EDS, Hg-porosimetry, BET area and N2 adsorption/desorption measurements. The oxidative stability of the developed materials was determined from mass loss in air measured by TGA tests. Macropores with confined Si3N4 crystals and SiC nano/micro one-dimensional structures, along with micro/mesopores located in cavity walls and within one-dimensional structure arrangements, were developed, resulting in high specific surface areas that make them potential materials for catalysts.