Yang Guangxu, Luo Xiaolin, Shuai Li
College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou, China.
Front Bioeng Biotechnol. 2021 Nov 18;9:770027. doi: 10.3389/fbioe.2021.770027. eCollection 2021.
Glucose produced by catalytic hydrolysis of cellulose is an important platform molecule for producing a variety of potential biobased fuels and chemicals. Catalysts such as mineral acids and enzymes have been intensively studied for cellulose hydrolysis. However, mineral acids show serious limitations concerning equipment corrosion, wastewater treatment and recyclability while enzymes have the issues such as high cost and thermal stability. Alternatively, solid acid catalysts are receiving increasing attention due to their high potential to overcome the limitations caused by conventional mineral acid catalysts but the slow mass transfer between the solid acid catalysts and cellulose as well as the absence of ideal binding sites on the surface of the solid acid catalysts are the key barriers to efficient cellulose hydrolysis. To bridge the gap, bio-inspired or bio-mimetic solid acid catalysts bearing both catalytic and binding sites are considered futuristic materials that possess added advantages over conventional solid catalysts, given their better substrate adsorption, high-temperature stability and easy recyclability. In this review, cellulase-mimetic solid acid catalysts featuring intrinsic structural characteristics such as binding and catalytic domains of cellulase are reviewed. The mechanism of cellulase-catalyzed cellulose hydrolysis, design of cellulase-mimetic catalysts, and the issues related to these cellulase-mimetic catalysts are critically discussed. Some potential research directions for designing more efficient catalysts for cellulose hydrolysis are proposed. We expect that this review can provide insights into the design and preparation of efficient bioinspired cellulase-mimetic catalysts for cellulose hydrolysis.
纤维素催化水解产生的葡萄糖是生产多种潜在生物基燃料和化学品的重要平台分子。人们对无机酸和酶等催化剂在纤维素水解方面进行了深入研究。然而，无机酸在设备腐蚀、废水处理和可回收性方面存在严重局限性，而酶则存在成本高和热稳定性等问题。相比之下，固体酸催化剂因其有潜力克服传统无机酸催化剂带来的局限性而受到越来越多的关注，但固体酸催化剂与纤维素之间传质缓慢以及固体酸催化剂表面缺乏理想的结合位点是纤维素高效水解的关键障碍。为弥补这一差距，兼具催化位点和结合位点的仿生或生物模拟固体酸催化剂被认为是未来的材料，鉴于其具有更好的底物吸附性、高温稳定性和易于回收利用的特点，相比传统固体催化剂具有更多优势。在本综述中，对具有纤维素酶结合和催化结构域等固有结构特征的仿纤维素酶固体酸催化剂进行了综述。对纤维素酶催化纤维素水解的机制、仿纤维素酶催化剂的设计以及与这些仿纤维素酶催化剂相关的问题进行了批判性讨论。提出了一些设计更高效纤维素水解催化剂的潜在研究方向。我们期望本综述能够为设计和制备用于纤维素水解的高效仿生仿纤维素酶催化剂提供见解。
