Carbon materials, which serve as common catalyst carriers, have been widely used and showed comparable stability, cost-effectiveness, and excellent efficiency in both academia and industry. Biomass, as a kind of abundant, low-cost, and green carbon source, can be prepared as carbon material and used as catalysts' carriers. There are two main methods for preparing carbon materials from biomass. One is the step-by-step preparation method including two steps processes. First, the biomass is prepared into porous carbon material through high-temperature activation decomposition, and then the required metal is loaded on the carbon material through the calcination method. The carbon material prepared by this method has better properties including larger specific surface area and multiple pore structures than the commercial activated carbon. Zhang 46 prepared microporous carbon materials using corn stalks, straw, and pine needles as the initial raw materials and KOH as the activator. The characterization showed that the specific surface area of the carbon materials was more than 3000 m 2 /g. Subsequently, Pt was loaded on the prepared carbon materials and then applied in the hydrogenation of cinnamaldehyde. They found that the catalyst showed better stability than the commercial carbon-supported catalyst during the catalyst's recycling test. The carbon materials prepared by biomass had more oxygen-containing functional groups and diverse pore structures, which were beneficial to the dissipation of reaction heat and prevented the sintering of the catalyst. The second method is in situ carbonization preparation, in which the precursor of carbon carrier is mixed with active phase metal salt and calcined at a certain temperature in an inert atmosphere. This method generally uses simple carbon-containing compounds as carbon sources, such as polyethylene glycol, melamine, and so on. Recently, the use of biomass as a carbon source to prepare carbon-based catalysts in situ has received more and more attention from researchers due to its cost-effective and environmental benefits. For example, Zhang and coworkers 47 used cotton as a carbon source and mixed it with nickel nitrate solution to prepare Ni/C catalyst through calcination at high temperature, then they applied it in the hydrogenation of o-chloronitrobenzene. Under 0.5 Mpa pressure of H2, the yield of chloroaniline could reach up to 100%. They used H2 instead of inert gases in the catalyst's preparation process. Later, Duan and co-workers 48 prepared the Co@NPC in a sequential hydrothermal and pyrolysis procedure starting from the bamboo shoots as raw materials. And the prepared shell Co@C catalyst doped with N and P showed excellent activity and selectivity for the hydrogenation of functionalized nitroarenes. In addition, the catalyst also exhibited high stability and could be recovered easily due to its magnetic properties. Lignin, as one of the most naturally abundant polymer materials extracted from biomass, has been poorly utilized as additives in building materials, basic raw materials for preparing low-value products like phenolic resins, and chemical monomers. Moreover, the large amounts of lignin produced from the pulp and paper industry were treated as waste and generated serious pollution to the environment. Developing a variety of methodologies for the utilization of lignin can not only provide a potential application of lignin but also release the environmental problems caused by lignin waste. Recently, the carbon materials prepared from lignin have been widely used in water or air purification, aerogels, and energy storage, due to their low cost, good thermal stability, high carbon content (60%), and a large number of benzene ring structures.