Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, FIN-00076 Espoo, Finland.
Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16 C, 106 91 Stockholm, Sweden.
ACS Nano. 2021 Apr 27;15(4):6774-6786. doi: 10.1021/acsnano.0c10307. Epub 2021 Mar 29.
Multiscale carbon supraparticles (SPs) are synthesized by soft-templating lignin nano- and microbeads bound with cellulose nanofibrils (CNFs). The interparticle connectivity and nanoscale network in the SPs are studied after oxidative thermostabilization of the lignin/CNF constructs. The carbon SPs are formed by controlled sintering during carbonization and develop high mechanical strength (58 N·mm) and surface area (1152 m·g). Given their features, the carbon SPs offer hierarchical access to adsorption sites that are well suited for CO capture (77 mg CO·g), while presenting a relatively low pressure drop (∼33 kPa·m calculated for a packed fixed-bed column). The introduced lignin-derived SPs address the limitations associated with mass transport (diffusion of adsorbates within channels) and kinetics of systems that are otherwise based on nanoparticles. Moreover, the carbon SPs do not require doping with heteroatoms (as tested for N) for effective CO uptake (at 1 bar CO and 40 °C) and are suitable for regeneration, following multiple adsorption/desorption cycles. Overall, we demonstrate porous SP carbon systems of low cost (precursor, fabrication, and processing) and superior activity (gas sorption and capture).
多尺度碳超粒子（SPs）是通过软模板法合成的，其方法是将木质素纳米和微球与纤维素纳米纤维（CNFs）结合。在木质素/CNF 结构物的氧化热稳定化之后，研究了 SPs 中的粒子间连接性和纳米级网络。在碳化过程中通过控制烧结形成碳 SPs，其具有高机械强度（58 N·mm）和表面积（1152 m·g）。鉴于其特性，碳 SPs 提供了对吸附位点的分级访问，非常适合 CO 捕获（77 mg CO·g），同时呈现出相对较低的压降（对于填充固定床柱计算约为 33 kPa·m）。所引入的木质素衍生 SPs 解决了与质量传递（吸附质在通道内的扩散）和动力学相关的限制，否则这些系统将基于纳米颗粒。此外，碳 SPs 不需要掺杂杂原子（如 N）即可有效吸收 CO（在 1 bar CO 和 40 °C 下），并且在经过多次吸附/解吸循环后，适合再生。总的来说，我们展示了低成本（前体、制造和加工）且具有高活性（气体吸附和捕获）的多孔 SP 碳体系。
