We report a discovery of a new member of the liquid organic hydrogen carrier (LOHC) family, 7-ethylindole (7-EID), with a low melting point of −14 °C and a decent hydrogen content of 5.23 wt%. Hydrogenation of the compound was carried out over a commercial 5 wt% Ru/Al₂O₃ catalyst in the H₂ pressure range of 5–8 MPa and a temperature range of 120–160 °C, respectively. It was found that the hydrogenation rate positively correlates with the reaction temperature. However, the rate was barely effected by the H₂ pressure if the pressure exceeds 6 MPa. The estimated apparent activation energy of 7-EID hydrogenation is 51.5 kJ/mol. The fully hydrogenated product, octahydro-7-ethylindole (8H-7-EID), was used as the reactant for the dehydrogenation reaction at 170–200 °C over a 5 wt% Pd/Al₂O₃ catalyst. Full dehydrogenation of 8H-7-EID to 7-EID can be achieved within 270 min at 190 °C. The apparent activation energy of 8H-7-EID dehydrogenation was calculated to be 101.9 kJ/mol at 170–200 °C. The liberated H₂ was found to be of high purity, which meets the requirement of proton exchange membrane fuel cells.

我们报告发现了液态有机氢载体（LOHC）家族的一个新成员7-乙基吲哚（7-EID），其低熔点为-14°C，氢含量为5.23 wt％。化合物的氢化分别在市售5 wt％Ru / Al ₂ O ₃催化剂上进行，H ₂压力范围为5-8 MPa，温度范围为120-160°C。发现氢化速率与反应温度成正相关。但是，该速率几乎不受H _2影响如果压力超过6 MPa，则为最大压力。估计的7-EID加氢表观活化能为51.5 kJ / mol。完全氢化的产物八氢-7-乙基吲哚（8H-7-EID）被用作在170-200°C的5wt％Pd / Al ₂ O ₃催化剂上进行脱氢反应的反应物。在190°C的270分钟内，可以将8H-7-EID完全脱氢为7-EID。在170–200°C下，8H-7-EID脱氢的表观活化能为101.9 kJ / mol。发现释放的H ₂具有高纯度，满足质子交换膜燃料电池的要求。