The diffusion barriers of organic molecules through the pores of the zeolite H-SSZ-13 are investigated using periodic DFT calculations at the PBE-D3 level of theory. We calculate the diffusion barriers relative to the most stable adsorbed state on the acid site of the zeolite and find that barriers range from ~70 kJ/mol for smaller molecules such as ethene and propene up to 350 kJ/mol for durene, the largest molecule investigated here. For larger molecules, the diffusion barriers can be correlated with the vdW-radius of the diffusing molecules. For smaller molecules, which generally have smaller diffusion barriers, there is no clear correlation between the barrier and the vdW-radius. Here, the strength of adsorption at the acid site is also extremely important in determining the diffusion barrier.

使用周期性的DFT计算在PBE-D3的理论水平上研究了有机分子通过H-SSZ-13沸石孔的扩散势垒。我们计算了相对于沸石酸性位置上最稳定吸附状态的扩散势垒，发现对于乙烯和丙烯等较小分子，势垒的范围从〜70 kJ / mol到最大分子杜勒烯的势垒范围为350 kJ / mol。在这里调查。对于较大的分子，扩散势垒可以与扩散分子的vdW半径相关。对于通常具有较小扩散势垒的较小分子，势垒与vdW半径之间没有明确的相关性。在此，酸位处的吸附强度对于确定扩散势垒也非常重要。