Glucose isomerization to fructose is one of the most important reactions in the field of biomass valorization. We demonstrate wood waste valorization with MgCl₂ salt to synthesize an environment-friendly catalyst (i.e., MgO-biochar), which exhibits effective glucose-to-fructose isomerization with over 30% fructose yield and 80% selectivity at only 100 °C for 30 min in water as a green medium. This study highlights that one-step synthesis can effectively disperse and tether MgO nanostructures to the biochar matrix, which displays a significant reduction of Mg leaching compared to MgO-biochars produced by two-step synthesis and pure MgO. The MgCl₂ acts as a porogen that facilitates the formation of a porous biochar structure and dispersion of nanostructured MgO. We identify key parameters of impregnation media (ethylene glycol, ethanol, and water) and pyrolysis conditions (600/750 °C in N₂/CO₂ atmosphere) that are responsible for adjusting the reactivity and stability of MgO, which enable the design of more effective and recyclable biochar catalysts. Weak interactions between MgCl₂ and biomass in the presence of aqueous miscible organic solvents as shape-directing agents are accountable for fast leaching of Mg from the MgO-biochar surface. The FTIR spectra confirm the existence of various coordinations on the hydroxylated surfaces of MgO-biochar surfaces. The mesoporous structures of the biochar support enhance the stability of MgO moieties as revealed by BET, XRD, and Raman analyses. Given the benefits of effective MgO dispersion on the biochar support, we can reduce the amount of MgO active species involved in each reaction run, which mitigates over-reaction compared to pure MgO catalysts and achieves high fructose yield and selectivity for three consecutive cycles.

中文翻译：

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MgO纳米结构在生物炭载体上的有效分散作为葡萄糖异构化的基本催化剂

葡萄糖异构化为果糖是生物质增值领域中最重要的反应之一。我们证明了用MgCl ₂盐对木材废料进行增值以合成一种环境友好型催化剂（即MgO-生物炭），该催化剂表现出有效的葡萄糖-果糖异构化作用，果糖收率超过30％，在100°C的条件下30选择性达到80％分钟在水中作为绿色介质。这项研究强调，一步合成可以有效地将MgO纳米结构分散并束缚到生物炭基质中，与两步合成和纯MgO产生的MgO生物炭相比，Mg浸出显着减少。氯化镁₂作为致孔剂，可促进多孔生物炭结构的形成和纳米结构MgO的分散。我们确定了浸渍介质（乙二醇，乙醇和水）和热解条件（在N ₂ / CO ₂气氛中为600 / 750°C）的关键参数，这些参数可调节MgO的反应性和稳定性，从而可以设计MgO。更有效和可回收的生物炭催化剂。MgCl ₂之间的相互作用弱水溶液和可混溶的有机溶剂作为定型剂存在下的生物质和有机物是导致MgO从生物炭表面快速浸出的原因。FTIR光谱证实了MgO-生物炭表面的羟基化表面上存在各种配位。BET，XRD和Raman分析显示，生物炭载体的介孔结构增强了MgO部分的稳定性。鉴于有效地将MgO分散在生物炭载体上的好处，我们可以减少每次反应运行中涉及的MgO活性物质的量，与纯MgO催化剂相比，可以减轻反应过度，并在三个连续循环中实现高果糖收率和选择性。