Abstract Three kinds of carbonaceous solid materials, namely activated carbon (AC), graphene oxide (GO), and graphene oxide–magnetite nanocomposite (GO/SCMNPs), have been utilized as catalyst supports to immobilize active acid sites on their surfaces. In this regard, three solid acid catalysts were prepared by a two-step synthetic approach: (a) surface chemical modification with a suitable nitrogen-containing spacer group and (b) chemical appending of sulfonic acid groups on the immobilized functional groups derived from step (a). Various methods have been exploited for characterization of the synthesized solid acid catalysts, such as FTIR and energy-dispersive X-ray (EDX) spectroscopies, elemental analysis, X-ray diffraction (XRD) analysis, N2 adsorption–desorption, thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The catalytic activities of these carbonaceous acid catalysts have been examined in an acetalization reaction using benzaldehyde and ethylene glycol as starting substrates. An outstanding result was achieved for the acid catalyst based on AC due to a higher concentration of incorporated sulfonic acid groups. Nevertheless, even the good efficiencies of the other two catalysts matched those of previously reported catalyst systems.

中文翻译：

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碳质材料磺化新方法：乙二醇苯甲醛缩醛的高效固体酸催化剂

摘要 三种碳质固体材料，即活性炭（AC）、氧化石墨烯（GO）和氧化石墨烯-磁铁矿纳米复合材料（GO/SCMNPs），已被用作催化剂载体以在其表面固定活性酸位点。在这方面，通过两步合成方法制备了三种固体酸催化剂：（a）用合适的含氮间隔基团进行表面化学改性和（b）在衍生自步骤的固定化官能团上化学附加磺酸基团。 （一种）。已利用各种方法来表征合成的固体酸催化剂，例如 FTIR 和能量色散 X 射线 (EDX) 光谱、元素分析、X 射线衍射 (XRD) 分析、N2 吸附-解吸、热重分析 (TGA) ) 和振动样品磁强计 (VSM)。已经在使用苯甲醛和乙二醇作为起始底物的缩醛化反应中检验了这些碳酸催化剂的催化活性。由于引入的磺酸基团的浓度更高，因此基于 AC 的酸催化剂取得了出色的结果。尽管如此，即使其他两种催化剂的良好效率也与先前报道的催化剂体系相匹配。