Abstract

The isotherms of absolute methane adsorption in an Fe–BDC metal–organic porous structure after long-term storage were measured at a pressure as high as 40 MPa and the temperatures of 303, 313, 323, and 333 K. The dependences of differential molar isosteric heats of adsorption and entropies of adsorption on methane uptake were calculated. It was shown that taking into account the nonideality of a gaseous phase and steepness of the isotherm of adsorption leads to a temperature dependence of thermodynamic functions of adsorption. Both a sharp drop in the heat of adsorption and a local maximum of the entropy at the maximum values of methane uptake are indicative of rearranging the adsorbate structure and the probable formation of molecular methane associates in micropores.

中文翻译：

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高压下Fе-BDC金属-有机多孔结构上的甲烷吸附

摘要

长期储存后，Fe-BDC金属-有机多孔结构中绝对甲烷吸附的等温线在高达40 MPa的压力和303、313、323和333 K的温度下进行测量。计算了吸附等排热和吸附熵对甲烷吸收的影响。结果表明，考虑到气相的非理想性和吸附等温线的陡度，会导致吸附的热力学函数与温度有关。吸附热的急剧下降和在甲烷吸收最大值处的熵的局部最大值都表明了重新排列了吸附物的结构以及在微孔中可能形成的甲烷分子缔合体。