Surface atom functionalization and the variation of aliphatic/aromatic structures within coal macromolecules are key factors to determine the pore structures within coalification. The characteristics of nano-micron scale pore structures were analyzed with the aid of coupled fluid intrusion and molecular probe technologies. Results indicate that the cleavage of long-chain aliphatic structures enhances the size of the pore throat and reduces the specific surface area and pore volume of the mesopores (2–50 nm). Macropores (>50 nm) were slightly impacted by coalification and their development was primarily controlled by diagenesis. Micropores (<2 nm) overall increase with the enhancement of aromatization and condensation polymerization; however, in the stage of low volatile bituminous, the blocking of minerals or low boiling hydrocarbon solids will temporarily reduce micropores. Meanwhile, similar surface structures and functional groups lead to similar characteristics of the pore size distribution for mesopores and micropores. Furthermore, the peak value of microporous pore volume migrates to the smaller pore size, and pores <0.4 nm in size generated from clearances among the aromatic layers gradually become dominant with coalification. The macropores fractal dimension (D_f1) is not only related to coalification. However, the heterogeneity and surface roughness of micropores (D_m) and mesopores (D_v2) are controlled by coalification. D_v1 of mesopores is affected by diagenesis. The pore walls are contributed by aliphatic structures before the third coalification jump. Meanwhile, micropores among aliphatic structures developed relatively independently and small-scale pore networks frequently exist within them. Accompanied by the cleavage of aliphatic structures, the aliphatic structures around the pore walls will be gradually replaced by the aromatic structure. Micropores of relative independence are decreased, and large-scale pore networks are gradually formed. The pore morphology developed to be more complex and strongly heterogeneous. In addition, high-density oxygen/nitrogen/sulfur functionalization will increase the micropores.

表面原子功能化和煤大分子内脂肪族/芳香族结构的变化是决定煤化过程中孔隙结构的关键因素。借助耦合流体侵入和分子探针技术，分析了纳米微米级孔隙结构的特征。结果表明，长链脂肪族结构的裂解增大了孔喉的尺寸，并降低了中孔（2-50 nm）的比表面积和孔体积。大孔（>50 nm）受煤化作用轻微影响，其发育主要受成岩作用控制. 随着芳构化和缩聚的增强，微孔（<2 nm）总体增加；但是，在低挥发沥青阶段，矿物或低沸点烃类固体会暂时减少微孔。同时，相似的表面结构和官能团导致中孔和微孔的孔径分布特征相似。此外，微孔孔体积的峰值向更小的孔径迁移，由芳烃层之间的间隙产生的尺寸<0.4 nm的孔随着煤化逐渐占主导地位。大孔分形维数（D_f1）不仅与煤化有关。然而，微孔的不均匀性和表面粗糙度（D_m) 和中孔 (D _v2 ) 受煤化控制。中孔的D _v1受成岩作用的影响。在第三次煤化跳跃之前，孔隙壁是由脂肪族结构贡献的。同时，脂肪族结构中的微孔相对独立发育，内部经常存在小尺度的孔隙网络。伴随着脂肪族结构的裂解，孔壁周围的脂肪族结构将逐渐被芳香族结构所取代。相对独立的微孔减少，逐渐形成大尺度的孔隙网络。孔隙形态发展为更加复杂和强烈的异质性。此外，高密度氧/氮/硫功能化将增加微孔。