Jianli Hu

Microwave-assisted acid activation creates an early kinetic window for preferential REE release relative to Fe, while thermomorphic [Hbet][Tf ₂ N] facilitates subsequent phase partitioning.

This article presents an ammonia synthesis strategy that utilizes H ₂ produced in‐situ as a byproduct of the methane coupling reaction. This approach eliminates the need for CO ₂ ‐intensive hydrogen production via steam methane reforming while lowering the operating temperature required for CH bond activation through microwave‐assisted (MW) catalysis. The process demonstrates strong potential for decarbonizing process heat via MW‐driven electrification. A two‐stage MW–thermal hybrid system is employed for the simultaneous activation of methane and nitrogen. In the first stage, methane undergoes nonoxidative coupling (NOCM) over a 1Cs–3Mo/CeO ₂ catalyst under MW irradiation, enabling stable CH activation and selective formation of C ₂ hydrocarbons with an apparent activation energy of 136 kJ·mol ⁻¹ . Ethylene is the dominant product below 750°C. The hydrogen‐rich effluent from the NOCM reactor is routed directly to a downstream Ru‐based catalytic reactor for ammonia synthesis, thereby eliminating the need for externally supplied hydrogen. Among the catalysts evaluated, 2Cs–4Ru/MgO exhibits the highest NH ₃ formation rate (0.60 mmol·g ⁻¹ ·h ⁻¹ ). The influence of cofed ethylene on NH ₃ productivity relative to conventional H ₂ /N ₂ feed is examined to assess competitive adsorption between olefins and ammonia. Catalyst characterization using chemisorption, NH ₃ ‐TPD, and operando Raman spectroscopy provides insights into surface chemistry relevant to NH ₃ formation. Operando Raman results indicate that the reduction of Ce ⁴⁺ to Ce ³⁺ generates oxygen vacancies that modify the electronic environment of adjacent Ru species, enhancing electron donation and strengthening back‐donation into the antibonding π* orbitals of adsorbed N ₂ . For the nitrogen circular economy, MW‐driven ammonia decomposition is demonstrated using monolithic catalyst. Overall, the MW–thermal hybrid platform offers a promising pathway toward decentralized and sustainable chemical manufacturing. Integration with renewable electricity and biomethane resources could further reduce the carbon footprint and enhance the overall sustainability of the system.

This work evaluates microwave-assisted calcination as a rapid, energy-efficient alternative to conventional resistive heating for complex oxide synthesis. Ce0.9Gd0.1O1.95 (GDC10) and La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF6428) were investigated using solid-state and co-precipitated precursors to assess the influence of precursor chemistry on microwave coupling, reaction kinetics, and powder characteristics. Experiments were conducted in a single-mode magnetic-field-extended reactor using a silicon carbide/alumina susceptor–insulation package to ensure uniform and reproducible heating. Microwave processing reduced calcination time to ~1 h, compared to >21 h in a conventional furnace, while yielding powders with 28% higher surface area. High-temperature dielectric measurements of LSCF (450–1000 oC) revealed strong temperature-dependent increases in dielectric constant and loss factor, governing self-heating behavior and distinct microwave-driven reaction pathways. Phase evolution and surface area were characterized by TGA, XRD, and BET. These results clarify microwave–material coupling mechanisms and demonstrate synergistic effects between precursor chemistry and microwave heating in complex oxide synthesis.

This study compares microwave and conventional thermal energy inputs for the hydrolysis and acetolysis of both virgin and postconsumer poly­(ethylene terephthalate) (PET). Reaction conditions in these experiments range from 200 to 300 °C and from 5 to 90 min. In no instances did the yields of terephthalic acid monomer or incompletely depolymerized PET demonstrate statistically significant or practically significant differences with these two different energy inputs. For fixed reaction conditions, yields of terephthalic acid were comparable from both methods, regardless of whether the reaction medium was water, acetic acid, or a mixture of the two. The visual appearance of the unreacted plastic was likewise the same for microwave and conventional thermal energy inputs when using identical solvents. These results suggest that the bulk fluid temperature is the controlling factor for PET depolymerization in a homogeneous fluid phase of water and/or acetic acid with no added catalyst. The reacting system responds similarly whether the heating is via microwave irradiation or via conduction across the reactor wall.

Ethylene is a critical feedstock in industrial processes, serving as a raw material in the petrochemical industry to produce plastics and commodity chemicals. Conventional ethylene production routes are energy-intensive and contribute substantially to the carbon footprint of chemical manufacturing. In this study, an industrial-scale novel microwave process was simulated using ASPEN Plus to assess its economic viability. Technoeconomic analysis confirmed the economic competitiveness of the novel microwave process, with a levelized cost of ethylene of USD 0.51/kg compared to USD 0.56/kg for the conventional base case. Key economic drivers of the process were identified, and sensitivity analyses were conducted to evaluate their impact on project economics. Furthermore, 87.7% of the total utility consumption in the novel microwave process is electricity, highlighting its potential to contribute to the electrification of the chemical industry. The findings of this study confirm the economic feasibility of both industrial-scale microwave reactors and modular plant configurations for the production of ethylene from methane, offering a promising alternative to conventional processes.

Polyethylene is the most used plastic in the world, and over 90% of this plastic is ultimately disposed of in landfills or released into the environment, leading to severe ecological implications. In this research, the technoeconomic feasibility of upcycling low-density polyethylene (LDPE) to produce ethylene is studied. The catalytic conversion of LDPE to ethylene is considered in microwave heating mode and Joule heating mode. Experimental data is obtained under conditions where most of the upcycled products are in the gas phase. A flowsheet is developed that produces industrial quantities of ethylene for both heating modes. A technoeconomic analysis and a life cycle analysis are conducted and compared with the traditional ethane cracking process for producing ethylene. Simulation results indicate that the upcycling system exhibits a lower capital expenditure and a comparable operating expenditure relative to conventional ethane steam cracking while generating additional valuable co-products, such as propylene and aromatic hydrocarbons, leading to a higher net present value potential. Sensitivity analyses reveal that the electricity price has the most significant impact on both the net present value and levelized cost of production, followed by the low-density polyethylene feedstock cost. Life-cycle assessment reveals a substantial reduction in greenhouse-gas emissions in the upcycled process compared to the fossil-based ethane steam-cracking route, primarily due to the use of renewable electricity, the lower reaction temperature that reduces utility demand, and the use of plastic waste as the feedstock. Overall, the proposed process demonstrates strong potential for the sustainable production of ethylene from waste LDPE.