The abundance of inherent micropores in biomass-based carbon restricts potassium ion transport, which in turn hinders both adsorption and intercalation kinetics. Increasing mesopore content can significantly enhance potassium ion transport, but quantitative regulation of mesoporous content remains challenging. Furthermore, the mechanism by which mesopore content affects reaction kinetics is not fully understood. In this work, carbon anodes with controlled mesopore content were synthesized by replicating SBA-15 zeolite structures via a coating method. For the first time, the relationship between mesopore content and potassium-ion storage performance is systematically explored. The increase in the mesopore content can both improve the enhance adsorption and intercalation kinetics, thereby improve the discharge capacity. However, excessive mesopores reduce the adsorption ratio, negatively impacting cycling stability. Therefore, an appropriate mesoporous content exhibits the best performance. This study offers a strategy for the regulation of mesopore content in carbon anodes and provides new insights into the role of mesopore content in enhancing potassium ions storage performance.

Oxygen content and specific surface area are key factors affecting the electrochemical performance of biomass‐derived hard carbon anodes for potassium‐ion batteries (PIBs). Increasing oxygen content enhances potassium storage, improving cycle stability and rate performance. Furthermore, optimizing porous structures boosts specific surface area, facilitating potassium ion diffusion and increasing capacity. Herein, a cost‐effective and environmentally friendly strategy is proposed, using bark as a precursor, oxygen as the oxidant, and pluronic P123 as the template agent. Oxygen‐doped porous hard carbon anodes are synthesized via pre‐oxidation and hydrothermal processing. These anodes exhibit large interlayer spacing, high specific surface area, and significant oxygen content, resulting in excellent electrochemical stability and capacity. The anodes maintain a high specific discharge capacity of 230.2 mAh g −1 after 200 cycles at 0.1 A g −1 , with minimal capacity loss. After 3000 cycles at 1 A g −1 , the capacity retention is 80%. This work demonstrates an effective method for utilizing bark to produce high‐performance hard carbon anodes for PIBs, advancing the development of bark‐derived materials for energy storage.

Carbonaceous anode showcases great potential for potassium‐ion batteries, yet their performance is unsatisfactory. Doping nitrogen atoms and increasing the specific surface area are two popular strategies for boosting the adsorption behavior, resulting in fast reaction kinetics, increased capacity, and long durability. However, rationally regulating the nitrogen content and specific surface area remains challenging, and their effect on adsorption behavior lacks quantified investigations. Here, we synthesize black liquor‐derived carbon anodes, where nitrogen content and specific surface area are precisely controlled through a chemical grafting strategy combined with varying pyrolysis temperatures. A concept of average adsorption sites is proposed for evaluating the adsorption behavior. For the first time, it is revealed that the adsorption ratio is linear and quantitatively regulated by average adsorption sites. Moreover, an ultrahigh adsorption contribution, low adsorption energy, and superior electrolyte wettability contribute to exceptional electrochemical performance. As a result, the anode achieved high capacities of 389.2 mAh g −1 after 200 cycles at 100 mA g −1 , 288.2 mAh g −1 after 2500 cycles at 1000 mA g −1 , and 183.7 mAh g −1 after 5000 cycles at 2000 mA g −1 . This study paves the way for rationally regulating the adsorption behavior of carbonous anode materials for potassium‐ion batteries.

In potassium-ion batteries, the large radius of potassium ions causes low discharge capacity and poor cycle performance of commercial graphite anode. Hard carbon materials have the potential to alleviate these problems owing to their large interlayer spacing and porous structure. Pre-hydrolysate, a type of wastewater biomass generated from the pulp and paper industry that is rich in sugars, is a suitable precursor for hard carbon. However, it is traditionally treated by burning it with black liquor, leading to inefficient utilization and environmental pollution. Therefore, new methods for efficiently utilizing pre-hydrolysate need to be explored. In this study, pre-hydrolysate was used to produce hard carbon anodes for potassium-ion batteries using a combination of hydrothermal and pyrolysis methods. The experimental results showed that the pre-hydrolysate-derived hard carbon anode achieved an excellent specific discharge capacity of 235.9 mAh g- 1 at 50 mA g- 1 after 200 cycles. Furthermore, it exhibited good cycling stability, with an average capacity decay rate of approximately 0.013 % per cycle at 500 mA g- 1 after 1000 cycles. This is the first study to integrate pre-hydrolysate with anode materials for potassium-ion batteries, offering a new research pathway for preparing potassium-ion battery anode materials and efficient utilization of pre-hydrolysate.

Because of the large ion radius of potassium and sluggish kinetics, high-performance anodes are required to release the horsepower of potassium-ion batteries. Calcium terephthalate emerges as an outstanding anode for potassium-ion batteries, due to its impressive combination of high discharge capacity and cycle stability. However, challenges arise from its intrinsic low conductivity and the reported high cost of calcium terephthalate. To address these issues, this study introduces a novel approach where carbon/calcium terephthalate composite anodes were synthesized to elevate electrochemical performance of potassium-ion batteries, where carbon and calcium terephthalate were completely derived and synthesized from waste polyethylene terephthalate and deinking sludge from a waste paper mill. The composite anodes exhibit remarkable potential as superior materials for potassium-ion batteries, demonstrating comparable performance to lithium-ion batteries using similar anodes as reported in literature. Furthermore, economic analysis underscores cost effectiveness of the proposed synthesis method. Ultimately, this research not only addresses the challenges associated with calcium terephthalate but also opens up the gate to directly utilize papermaking wastes to develop high-performance anode materials for potassium-ion batteries.

Pyrolysis holds immense potential for clean treatment of pulp and paper mill sludge (PPMS), enabling efficient energy and chemical recovery. However, current understanding of PPMS pyrolysis kinetics and product characteristics remains incomplete. This study conducted detailed modeling of pyrolysis kinetics for two typical PPMSs from a wastepaper pulp and paper mill, namely, deinking sludge (PPMS-DS) and sewage sludge (PPMS-SS), and analyzed comprehensively pyrolysis products. The results show that apparent activation energy of PPMS-DS (169.25-226.82 kJ/mol) and PPMS-SS (189.29-411.21 kJ/mol) pyrolysis undergoes significant change, with numerous parallel reactions present. A distributed activation energy model with dual logistic distributions proves to be suitable for modeling thermal decomposition kinetics of both PPMS-DS and PPMS-SS, with coefficient of determination >0.999 and relative root mean square error <1.99 %. High temperature promotes decomposition of solid organic materials in PPMS, and maximum tar yield for both PPMS-DS (53.90 wt%, daf) and PPMS-SS (56.48 wt%, daf) is achieved at around 500 °C. Higher levels of styrene (24.45 % for PPMS-DS and 14.71 % for PPMS-SS) and ethylbenzene (8.61 % for PPMS-DS and 8.33 % for PPMS-SS) are detected in tar and could be used as chemicals. This work shows great potential to propel development of PPMS pyrolysis technology, enabling green and sustainable production in pulp and paper industry.

Porous hard carbon anodes, with large interlayer space and high adsorption ability, can offer much better cycle stability and higher discharge capacity for potassium-ion batteries compared to commercial graphite anodes. However, most commercial hard carbons are synthesized from relatively expensive high-molecular polymers. In this study, pulping and papermaking wastes were utilized as precursors for producing hard carbons and poreenlarging agent, respectively. Specifically, after thorough mixing through ball milling, black liquor solids and deinking sludge were utilized to produce porous hard carbon anodes via co-pyrolysis. The results show that direct pyrolysis of black liquor can produce hard carbons efficiently, eliminating the need to extract lignin from black liquor. Moreover, it is shown that the pore-enlarging agent derived from deinking sludge can enlarge much portion of pores on hard carbons, resulting in abundant mesopores. Electrochemical tests demonstrate that the synthesized porous hard carbon anodes can achieve highest specific capacity of 303.5 mAh g- 1 at 100 mA g- 1 using a 1.0 M potassium hexafluorophosphate electrolyte in a mixture of diethyl carbonate and ethylene carbonate. Additionally, the synthesized porous hard carbon anodes exhibit low average capacity decay per cycle of 0.06 % at 100 mA g- 1 when tested with a 1.0 M potassium bis(fluorosulfonyl)imide electrolyte in the same solvent mixture after 500 cycles. Therefore, recycling black liquor and deinking sludge to produce porous hard carbon anodes for potassium-ion batteries is a promising approach for environmental and energy sustainability.

采用共沉淀法合成了MnCo2O4催化剂,并采用水热法合成了氧化锰八面体分子筛(OMS-2)催化剂,与NaY分子筛催化纤维素热解效果对比后对NaY进一步改性,采用浸渍法制备了Co/NaY、Sn/NaY以及Co-Sn/NaY,并研究了所制备催化剂对纤维素热解气催化重整制备呋喃类化合物的影响.采用氮气吸附-脱附、X射线衍射(XRD)仪、扫描电镜显微镜(SEM)和氨气吸附-脱附法(NH3-TPD)对催化剂进行表征.实验结果表明:金属Co、Sn分散在NaY表面,且没有改变NaY的晶体结构和形貌;负载后催化剂的比表面积和孔容减小,平均孔径增大,且比表面积远大于MnCo2O4、OMS-2;负载Sn几乎不改变NaY分子筛的酸性位点,而Co会减少酸性位点.几种催化剂的加入均促进了醇类、酸类、醛类的生成,抑制了糖类的生成.在纤维素与催化剂的质量比为1:14的条件下,NaY和Co/NaY均能够显著提高呋喃类化合物质量分数,从未添加催化剂的15.34％分别提高到了48.16％和61.88％,金属负载NaY催化剂均促进了呋喃酮的生成,抑制了呋喃的产生.

Catalytic fast pyrolysis of biomass is an effective strategy for the preparation of high value-added liquid fuels or chemicals. Understanding the effects of different biomass materials on the physicochemical property changes of ZSM-5 is important for the design of modified catalysts and targeted regulation of products. In this study, the catalytic upgrading of lignocellulosic biomass over ZSM-5 was investigated. Lignin, cellulose and xylan were used as model compounds of lignocellulosic biomass, and the upgraded products were analyzed online. Several techniques were used to gain a deep understanding of the physiochemical changes in ZSM-5. The results showed that the addition of ZSM-5 contributed to the production of aromatic hydrocarbons and olefins. The crystal structure and morphology of ZSM-5 were not changed, but the total acid, Bronsted and Lewis acid contents decreased. The amount of coke deposited on ZSM-5 follows the order cellulose/ZSM-5 > xylan/ZSM-5 > lignin/ ZSM-5. Coke on cellulose/ZSM-5 has the lowest H/C ratio of 0.50. Coke on ZSM-5 will create new micropores and increase the specific surface area of micropores.

Hydrodeoxygenation of lipids is a promising method to produce diesel-like hydrocarbons. In this work, NiO/TS-1 and Ni/TS-1 catalysts were synthesized, and the catalytic hydrodeoxygenation of palmitic acid to produce diesel-like hydrocarbons was investigated. The effect of reaction time (2-10 h) and H-2 pressure (1-5 MPa) on the production of diesel-like hydrocarbons were also studied in detail. Finally, a possible reaction route was proposed. The results showed that catalytic hydrodeoxygenation performance is affected by the valence of active component Ni. Ni/TS-1 shows better catalytic performance than NiO/TS-1 in terms of palmitic acid conversion and alkanes selectivity. Under the optimal experimental conditions (260 degrees C, 4 MPa, 10 h, 400 rpm), the palmitic acid conversion and pentadecane selectivity over Ni/TS-1 are 100% and 91.6%, respectively. It is found that hexadecanol is an important intermediate in the hydrodeoxygenation of palmitic acid.

In order to improve the quality of bio-oils, catalytic fast pyrolysis of corncob over Pt/Re supported activated carbon (AC) catalysts was conducted to produce bio-furans and bio-phenols. The effect of Pt/Re ratio on the catalytic pyrolysis performance was evaluated. Pt and Re are uniformly dispersed on AC, but it results in the decrease of specific surface area. In addition, the amount of weak acidic sites increased and higher total weak acidity of Pt-Re/AC was contributed to the production of target products at low catalytic upgrading temperature. AC and Pt/AC inhibited the formation of phenols, and Re/AC and Pt-Re/AC promoted the formation of phenols. The relative peak area of furans over 1Pt-3Re/AC and Re/AC is 44.36 % and 41.98 %, respectively. Pt-Re/AC catalysts have a high selectivity for methylfurans (MFs) and phenol (P), remaining at 19 % - 33 % and 17 % - 21 %, respectively. Finally, 1Pt-3Re/AC showed good reuse performance.

The production of high-valuable chemicals, such as furans, from biomass is a hot topic in the past decade. It used to be abstracted from fossil resources. This paper presents a study on the production of furan compounds via catalytic pyrolysis of cellulose on a two-staged fixed-bed reactor. Four solid acidic catalysts including Nb2O5, γ-Al2O3, ZSM-5, and TS-1, were used for the catalytic cracking. The selectivity of furans is 9.6% in a blank test and increased to 43.9% and 20.7% over TS-1 and Nb2O5, respectively. Nevertheless, ZSM-5 and γ-Al2O3 lowered the furan selectivity to 6.8% and 8.8%, respectively. The relationship between the physicochemical properties of different catalysts and their catalytic selectivity towards furan compounds were discussed based on characterization results of N2 physisorption, XRD, NH3-TPD, Py-IR, and TG/DTG.

How to reduce reaction pressure and hydrogen consumption is a hot and difficult issue for the conversion of biomass to produce alkanes. In this research, vapors from cellulose pyrolysis were converted into alkanes without extra hydrogen source. The effect of content of Au loading, mass ratio of catalyst to cellulose, pyrolysis and catalytic temperature on the production of LCAs was studied. Model compounds were used to explore possible mechanism for the formation of LCAs. At the optimal reaction condition, the highest selectivity and yield of LCAs were 89.2% and 14.4 wt%, respectively, over 1.0% Au/TS-1. Alcohol functional groups are contributed to the formation of LCAs over Au/TS-1.

Analytical pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC×GC/MS) was employed for the on-line analysis of catalytic pyrolysis products distribution and furans selectivity of corncob. Different catalysts (TiO2, ZrO2, MCM-41 and activated carbon (AC)) and catalytic temperature (350 °C, 400 °C, 450 °C and 500 °C) were investigated. The catalysts were subjected to several characterization methods, including temperature programmed decomposition of ammonia (NH3-TPD) and N2 adsorption-desorption, to investigate the effects of physical-chemical properties of the catalysts on products distribution and furans selectivity. The experiment results showed that a lower catalytic temperature (≤ 400 °C) was conductive to form furans and higher catalytic temperature (≥ 450 °C) was promoted hydrocarbons formation, among the four catalysts. The AC catalyst gave higher furans relative peak area (54.48%) than other catalysts (31.24% ~ 41.99%). And higher total acidity (weak acidity) of AC was favored for the formation of furfural and furan, 2-methyl- at 350 °C. Moreover, AC had the great thermal stability, and the catalyst recycling tests showed that the prepared AC can be reused for five times in furan-rich bio-oil production. After cycle, the relative peak area of furans also maintained above 40%. In addition, furan, 2-methyl- always maintained a high relative peak area (8%). It was expected that four type catalysts can be widely used for biomass catalytic conversion to produce furans processes at low catalytic temperature, especially the AC.

Production of alkanes from bio-oil is usually conducted under a rigorous condition with high hydrogen consumption. In this study, a novel method for long-chain alkanes production via catalytic upgrading of cellulose pyrolysis vapors over Au/TS-1 catalyst under a mild condition without hydrogen and normal pressure was reported. Catalytic upgrading of cellulose was performed on a dual pyrolyzer (Py) coupled with gas chromatograph/mass spectrometry (GC/MS). The experimental results showed that Au/TS-1 could effectively decrease the oxygen content of bio-oil from 100 % to 21 %, and increase the selectivity of alkanes from 0 % to 76.7 %. Glucose, methanol and n-pentane were used as model compounds to understand the possible upgrading mechanism for the formation of hydrocarbons, and it is shown that the long-chain alkanes were generated from methyl and hydroxyl dehydration.

Analytical pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC x GC/MS) was employed for the on-line analysis of cellulose via catalytic pyrolysis with different catalysts and catalytic temperatures to study the products and aromatic hydrocarbons selectivity. The catalysts were subjected to characterization methods, including XRD, TEM, NH3-TPD, to investigate the effects of the physicochemical properties of the catalyst on the product distribution. Results showed that the Ce0.8Zr0.2-xAlxO2 could significantly promote the formation of aromatic hydrocarbons under 400-550 degrees C. A lower catalytic temperature (<= 350 degrees C) favored the formation of furan compounds, and a higher catalytic temperature (<= 450 degrees C) supported the formation of aromatic hydrocarbons. The relative peak area of the aromatics prepared by using the Ce0.8Zr0.15Al0.05O2 catalyst was the highest being 85.24% at 550 degrees C. Moreover, the selectivity of the single-ring aromatics, such as benzene, toluene and xylene, were significantly affected by the presence of the Ce0.8Zr0.2xAlxO2 catalysts. The higher total acidity of Ce0.8Zr0.15Al0.05O2 favored the formation of benzene and toluene. Additionally, the Ce0.8Zr0.15Al0.05O2 catalyst had a great thermal stability. The catalyst recycling tests showed that the Ce0.8Zr0.15Al0.05O2 catalyst can be reused five times to produce aromatic-rich bio-oil via catalytic fast pyrolysis.

Analytical pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC x GC/MS) was used for the on-line analysis of pyrolysis vapors. Bio-based activated carbon (B-AC) catalysts were used to produce highly selectivity valuable chemicals such as furans and phenols. B-AC catalyst was subjected to several characterizations to investigate the physicochemical properties of the catalyst and its relationship with products distribution. The results showed that B-AC catalyst showed high catalytic activity and selectivity for the production of furans and phenols under mild catalytic temperature (350 degrees C). Furans are mainly from pyrolysis of cellulose and hemicellulose, while phenols are mainly from pyrolysis of lignin. Methylfurans and phenol were dominated compounds. With the use of B-AC, the relative peak area of methylfurans increased from 6.58% to 39.35% (cellulose), 0%-27.79% (xylan), 0.54%-26.82% (corncob); the relative peak area of phenol increased from 6.31% to 53.83% (lignin) and 2.77%-12.34% (corncob). A significant reduction of aldehydes, ketones, and sugars was also observed over B-AC catalyst. The higher total acidity (weak acidity and Lewis acidity) of B-AC favored the formation of 2-methylfuran and phenol.

Catalytic upgrading of biomass pyrolysis products was an important way for converting biomass to high-value chemicals. Catalytic pyrolysis process produced a higher-oxygenated containing bio-oil over 100 compounds. Furan compounds (furans) were important green platform chemicals in organic synthesis. In order to find a new route for production of furans from catalytic pyrolysis of lignocellulosic biomass by gas-solid heterogeneous catalyst, catalytic conversion of biomass into furan yield and selectivity with catalytic pyrolysis vapor upgrading over different types of catalysts (Al2O3, MCM-41, AC (Activated Carbon), HZSM-5 (Si/Al=38, 46, 80), TiO2 and ZrO2) were investigated. Simultaneously, the response surface methodology was used to determine the optimum process conditions of catalytic pyrolysis of corncob by using MCM-41, AC and TiO2 as catalysts. The results showed that MCM-41 and AC catalysts had the largest specific surface area, followed by HZSM-5, while Al2O3, ZrO2 and TiO2 had the opposite results. In addition, all the catalyst belonged to mesoporous catalysts with the average pore size of 3-16 nm. The main components of corncob with non-catalytic pyrolysis were aldehydes and ketones (17.62%), furans (22.55%) and aromatic compounds (25.18%). Moreover, 4-hydroxy-3-methylacetophenone, 2,3-dihydro-benzofuran and catechol had the highest contents, which were 8.65%, 13.1% and 4.01% respectively. All catalysts inhibited the formation of acid compounds, especially, when AC and HZSM-5(80) were added, the acidic compounds disappeared. The formation of aldehydes and ketones was not significant with the presence of ZrO2, and was inhibited by other types of catalysts. And, HZSM-5 (38), HZSM-5 (46) and AC enhanced the formation of aromatic hydrocarbon, which increased by 1.82%, 14.12% and 12.64% respectively. However, other catalysts were facilitating the formation of furans, which increased by 7.89% (TiO2), 8.88 %( MCM-41), 6.23 %( AC) and 4.95 %( ZrO2), respectively compared with non-catalytic pyrolysis. The maximum yield of furfural of 3.46% was obtained (catalyst is AC) under the conditions of catalytic pyrolysis temperature of 500 ℃ and mass ratio of corncob to catalyst of 2:1. Both TiO2 and HZSM-5 catalysts promoted the formation of furfural, but the effect was not significant. The other catalysts inhibited the formation of furfural. The influence of HZSM-5 catalyst on 2 (5H) -furanone was small, while the other catalysts promoted the production of 2 (5H) -furanone, the maximum yield was obtained with the presence of MCM-41, which increased by 5.45%. And the addition of catalyst inhibited the formation of -benzofuran-2,3-dihydrogen and 5-hydroxymethylfurfural. All the catalysts promoted the production of 5-methyl-2(3H) -furanone except for Al2O3. A highly fitting regression equation was obtained by using the response surface methodology to optimize the preparation process of furans compounds produced by catalytic pyrolysis of corncob, which could effectively predict the yield of furans. The order of effect parameters on the yield of furans was as follows: catalyst > catalytic pyrolysis temperature > mass ratio of corncob to catalyst. The yield of furans could reach 35.30% at the optimum process conditions of catalytic pyrolysis temperature of 550℃ and the mass ratio of corncob to catalyst of 1:1 by using AC catalyst. It would provide a basis for the catalytic pyrolysis of lignocellulosic biomass for production of high value-added chemicals by using heterogeneous catalysts at gas-solid catalytic reaction conditions. And it would provide a new pathway for furans production.