图文解析a、材料合成与表征通过简单的溶剂热反应得到了黄色晶态的UPC-COF-1和UPC-COF-2，用XRD，SEM，TEM，BET等表征证明材料的晶态，通过理论模拟结合实验分析确定两个材料的结构组成。 Figure 1.(a) Schematic illustration of the synthesis of UPC-COF-1 and UPC-COF-2. The refined 2D structures of (b) UPC-COF-1 and (c) UPC-COF-2 with AA stacking mode. Figure 2.The simulated, experimental, and refined PXRD patterns of (a) UPC-COF-1 and (b) UPC-COF-2. SEM images of (c) UPC-COF-1 and (d) UPC-COF-2. HRTEM images of (e) UPC-COF-1 and (f) UPC-COF-2. b、吸附分离性能研究Figure 3.(a) N2 adsorption-desorption isotherms and (b) pore size distribution of UPC-COF-1 and UPC-COF-2 at 77 K. Single-component adsorption-desorption isotherms of (c) UPC-COF-1 and (d) UPC-COF-2 for C2H2 and CO2 at 273 and 298 K. (e) Adsorption enthalpy of UPC-COF-1 and UPC-COF-2 for C2H2 and CO2. (f) Comparison of C2H2 uptake and IAST selectivity of equimolar C2H2/CO2 with reported C2H2-selective COFs at 298 K and 100 kPa. 在298 K，UPC-COF-1和UPC-COF-2的C2H2吸附量达到89.8和55.0 cm3/g，而CO2的吸附量仅为45.5和23.5 cm3/g。值得注意的是，C2H2的吸附量高于许多报道的C2H2选择性COF（仅次于BNOF-1）。通过计算UPC-COF-1和UPC-COF-2吸附焓,衡量COF框架对气体分子的亲和力。UPC-COF-1和UPC-COF-2的C2H2吸附焓均高于CO2，表明与C2H2的亲和力更强。同时，UPC-COF-1的吸附焓差值和分离选择性都明显高于UPC-COF-2，表明较窄的孔径有助于气体分离，动态穿透实验也进一步证实这一点。此外UPC-COF-1可以在存在水蒸气和甲烷杂质的情况下保持分离稳定性，表明其在实际工业条件下的应用潜力。 Figure 4.(a) Dynamic breakthrough curves of equimolar C2H2/CO2 binary mixture (2 mL/min) on UPC-COF-1 and UPC-COF-2 at 298 K. Cycling breakthrough tests of equimolar C2H2/CO2 binary mixture (2 mL/min) on UPC-COF-1 (b) under dry condition and (c) under humid condition (R.H. = 80%) at 298 K. (d) Cycling breakthrough tests of C2H2/CO2/CH4 ternary mixture (1/1/3, 5 mL/min) on UPC-COF-1 at 298 K. The optimal adsorption site and binding energy of (e) C2H2 and (f) CO2 in UPC-COF-1 and (g) C2H2 and (h) CO2 in UPC-COF-2. Distances are given in Å. c、理论计算理论计算表明，气体优先吸附位点位于环戊二烯钴基团附近，表明其与气体分子的强亲和力。在UPC-COF-1和UPC-COF-2中，通过DFT计算得到C2H2和CO2的结合能进一步证明了更短的构建单元、更窄的孔径的UPC-COF-1具有更强的主-客体相互作用，因而展现出更优的C2H2/CO2分离性能。
