Lignin was isolated from wheat straw via organosolv process and further transferred to monophenolic compounds via oxidative conversion. Wheat straw lignin (WSL) with purity at 91.4 wt% was acquired in the presence of heterogeneous and recyclable catalyst of Amberlyst‐45. WSL was characterized by infrared spectrometer (IR), nuclear magnetic resonance spectroscopy (NMR) including ¹H NMR and ¹³C NMR spectra. The results showed that WSL possesses typical syringyl (S), guaiacyl (G), and p‐hydroxyphenyl (H) units, and it is mainly composed of S and G units. The product distribution was dependent on the composition of WSL. Derivatives from S and G units were found to be the main products. The oxidative conversion of WSL was performed by varying oxidant and catalyst. Both the formation of monophenolic compounds and aromatic aldehydes were enhanced by combining oxidants and catalysts. The composite catalyst composed of NaOH/NaAlO₂ was effective for the oxidation of WSL in the presence of nitrobenzene and atmospheric pressure air. The total yield of monophenolic compounds reached up 18.1%, and yields at 6.3 and 5.7% for syringaldehyde and vanillin were achieved, respectively.

中文翻译：

---

NaOH / NaAlO2催化从麦秸中分离出的木质素氧化转化为芳香族化合物。

木质素通过有机溶剂法从小麦秸秆中分离出来，并通过氧化转化进一步转化为单酚类化合物。在Amberlyst-45异构且可回收的催化剂存在下，获得了纯度为91.4 wt％的小麦秸秆木质素（WSL）。WSL通过红外光谱仪（IR），核磁共振光谱（NMR）进行表征，包括¹ H NMR和¹³ C NMR光谱。结果表明，WSL具有典型的丁香基（S），愈创木基（G）和p-羟苯基（H）单元，主要由S和G单元组成。产品分布取决于WSL的组成。发现来自S和G单元的衍生物是主要产品。通过改变氧化剂和催化剂进行WSL的氧化转化。通过组合氧化剂和催化剂，单酚化合物和芳族醛的形成均得到增强。由NaOH / NaAlO ₂组成的复合催化剂在硝基苯和大气压空气存在下对WSL的氧化有效。单酚类化合物的总收率提高了18.1％，丁香醛和香兰素的收率分别达到6.3和5.7％。