This review offers a focused discussion on the recent progress of biomass-derived nitrogen-doped porous carbon (NPC) and its applications. Various synthesis methods for biomass-derived NPCs are introduced and critically reviewed. N-doping is a promising approach for further improving the physicochemical/electrochemical properties of carbon materials. Besides, NPC synthesis from inexpensive biomass for energy storage applications is a green and sustainable strategy. NPCs can be synthesized directly from algae, chitosan, and glucosamine without using any additional N precursor. The effect of synthesis methods on the physicochemical properties of NPCs offers a direction for optimizing the properties of NPCs for diverse applications. The utilization of NPCs in various applications, including catalysis and electrochemical energy storage (e.g., fuel cells, batteries, and supercapacitors), is reviewed. Besides, a discussion on the use of NPCs in oxidation and hydrogenation reactions, CO₂ capture and reduction is provided. The factors controlling the electrocatalytic performance of NPC are evaluated, such as the effect of N-content and the type of N species in NPCs. Finally, to improve the rational design of biomass-derived NPCs for catalysis and energy storage applications, an outlook and conclusion are provided.

The conversion of raw biomass into C5-sugars and furfural was demonstrated with the one-pot method using Brønsted acidic ionic liquids (BAILs) without any mineral acids or metal halides. Various BAILs were synthesized and characterized using NMR, FT-IR, TGA, and CHNS microanalysis and were used as the catalyst for raw biomass conversion. The remarkably high yield (i.e. 88%) of C5 sugars from bagasse can be obtained using 1-methyl-3(3-sulfopropyl)-imidazolium hydrogen sulfate ([C₃SO₃HMIM][HSO₄]) BAIL catalyst in a water medium. Similarly, the [C₃SO₃HMIM][HSO₄] BAIL also converts the bagasse into furfural with very high yield (73%) in one-pot method using a water/toluene biphasic solvent system.

Development of a competent method for the conversion of hemicellulose, a lignocellulosic component, into sugars is essential. In a one-pot method, Brönsted acidic ionic liquid (BAIL)-catalyzed hydrolysis of hardwood hemicellulose at 160 °C in water media gave C5 sugars (xylose + arabinose) in 87% yield. The efficiency of the ILs and their acid strength both followed the similar trend, [C₃SO₃HMIM][HSO₄] > [C₃SO₃HMIM][PTS] > [C₃SO₃HMIM][Cl] > [BMIM][Cl]. The ion–dipole-type interaction present between the BAIL and the substrate, which is proposed by the ¹H NMR study, is suggested to help in achieving better activity with BAIL than with mineral acid, H₂SO₄.

We describe the selective hydrogenation of furfural (FAL) into tetrahydrofurfuryl alcohol (THFA) under mild conditions (30 °C) in aqueous media using an Rh-loaded carbon (Rh/C) catalyst in a one-pot fashion. In FAL hydrogenation, the Rh/C catalyst showed a high THFA yield (92%) with 93% selectivity in aqueous media within 12 h, whereas the use of a dimethylacetamide (DMA) solvent system resulted in a 95% THFA yield within 32 h at 30 °C. The study of the effect of the solvent on FAL hydrogenation reveals that polar solvents showed higher THFA yields than a toluene solvent. The Rh/C catalyst used in this study exhibited higher activity compared to Ru/C, Pd/C, Ni/C derived from Ni-based metal–organic framework (Ni-MOF), and Ni-loaded carbon black (Ni/CB) catalysts in FAL-to-THFA hydrogenation. The Rh/C catalyst is characterized in detail using various characterization techniques such as TEM, XRD, N₂-adsorption–desorption, XPS, and ICP-OES to understand its physicochemical properties. The Rh/C catalyst shows similar high THFA yields in the recycling experiment of FAL hydrogenation under ambient conditions.