Identification of synergies in polyaniline supported cobalt polyphthalocyanine for efficient and selective CO2 electroreduction to CO.

This study investigates the incorporation of a standardised flexibility protocol within a physics-based models to enable controllable demand-side flexibility in residential energy systems. A heating subsystem is developed using MATLAB/Simulink and Simscape, serving as a testbed for protocol-driven control within a Multi-Energy System (MES). A conventional thermostat controller is first established, followed by the implementation of an OpenADR event engine in Stateflow. Simulations conducted under consistent boundary conditions reveal that protocol-enabled control enhances system performance in several respects. It maintains a more stable and pronounced indoor–outdoor temperature differential, thereby improving thermal comfort. It also reduces fuel consumption by curtailing or shifting heat output during demand-response events, while remaining within acceptable comfort limits. Additionally, it improves operational stability by dampening high-frequency fluctuations in mdot_fuel. The resulting co-simulation pipeline offers a modular and reproducible framework for analysing the propagation of grid-level signals to device-level actions. The research contributes a simulation-ready architecture that couples standardised demand-response signalling with a physics-based MES model, alongside quantitative evidence that protocol-compliant actuation can deliver comfort-preserving flexibility in residential heating. The framework is readily extensible to other energy assets, such as cooling systems, electric vehicle charging, and combined heat and power (CHP), and is adaptable to additional protocols, thereby supporting future cross-vector investigations into digitally enabled energy flexibility.

In this paper, the performance of a hot air turbine operating in an industrial combined heat and power (CHP) cogeneration is investigated, electrical and thermal energy supplied are intended for a pellet production unit. This unit is powered by Eucalyptus residue at 50% moisture content recovered from a forest located in El Taref, north-east of Algeria. The results show that when the air temperature at the boiler inlet Te exceeds 100 degree C, an excess air ratio, alpha, above 90% is required to maintain the flame temperature below 1200 K. Based on this, the parameters were set to alpha = 80% and Te = 100 degree C, resulting in a flame temperature of 1192K. The turbine inlet temperature T3, which must remain below the flame temperature, was fixed at 1140K. Once these conditions were established, the compression ratio maximizing the overall efficiency was determined to be around 8, yielding a cogeneration efficiency of 53%, with an electrical efficiency of 20% and a thermal efficiency of 33%.

This study presents a comprehensive evaluation of a modified membrane cascade operating in “Continuous Membrane Column” mode for selective CO2 capture in combined heat power plants. For the first time, a novel membrane cascade configuration for separating four-component wet flue gases is analyzed and compared with existing technologies in terms of the capital and operating costs required to capture one ton of CO2. The proposed membrane cascade generates two countercurrent recirculating streams: one continuously depleted of the permeate component and the other enriched in it. Because the internal recirculation streams significantly exceed the bypass product streams, the system demonstrates a multiplicative increase in separation efficiency. As a result, the required membrane area and compression energy can be significantly reduced. The analysis demonstrates that the proposed cascade configuration meets all current performance requirements for CO2 recovery and the target composition of the product and residual streams. Furthermore, due to its balanced material and energy cost ratio, the system can serve as a competitive alternative to previously developed membrane CO2 capture technologies, offering lower overall capture losses.

A comparative study of CeO2-decorated Co(OH)2 and CoOOH highlights the critical role of substrate dynamics. Operando spectroscopic studies reveal that the interface derived from Co(OH)2 efficiently stabilizes oxygen vacancies. Such vacancy stabilization promotes the formation of high-valent CoO2 species, thereby enhancing oxygen evolution performance.

The development of efficient molecular catalysts for electrochemical CO2 reduction (ECO2R) remains a key challenge for scalable carbon utilization. Herein, we report the synthesis and electropolymerization of an α-tetraamino-substituted CoII-phthalocyanine monomer (CoPc-1α) to yield robust polymer films (p(CoPc-1α)) on various conductive substrates. The resulting films were characterized by UV-visible spectrophotometry, Raman and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX), variable frequency square-wave voltammetry (VF-SWV), and density functional theory (DFT), confirming successful polymer network formation via phenazine linkages and efficient electron transfer across macrocyclic units. In H-cell electrolysis at -1.15 V vs. NHE, a p(CoPc-1α)-modified carbon paper electrode exhibited high selectivity for CO generation with a faradaic efficiency (FECO) of 97%, along with a current density of 3.8 mA cm-2 and a turnover number (TONCO) and a turnover frequency (TOFCO) of 6.0 × 104 and 0.37 s-1, respectively, over 45 h. At an applied potential of -1.54 vs. NHE in a flow-cell system, the p(CoPc-1α) film on a microporous layer of a carbon fiber paper exhibited remarkable catalytic performance, achieving an average current density of 151 mA cm-2 with 98% FECO for 42 h, corresponding to a TONCO of 1.9 × 106 and a TOFCO of 12.6 s-1. This study demonstrates that p(CoPc-1α) offered a balanced profile of high selectivity, long-term stability and practical current output, establishing it as a promising material for scalable CO2-to-CO conversion.

The atom programming of multiple active centers is a central goal in advanced catalysis, yet it remains a formidable challenge, particularly for complex transformations like CO2 photoconversion that require orchestrated multi-electron/proton pathways. Herein, we report an orthogonal site-encoding strategy, driven by coordination adaptability, that enables unprecedented atomic-level spatial programming within a dual-metal covalent organic framework (TZCOF), featuring precisely positioned intralayer CoNOCl2 and interlayer NiN2Cl2 sites. This architecturally programmed CoNi-TZCOF exhibits exceptional performance, with a CO generation rate of 13.6 mmol g-1 h-1 (98.7% selectivity), significantly outperforming pristine TZCOF (51.6% selectivity), Co-TZCOF (88.5% selectivity), and Ni-TZCOF (85.9% selectivity) by factors of 41.2, 1.3, and 6.2, respectively. Moreover, in simulated flue gas containing 15% CO2, CoNi-TZCOF also displays excellent CO production activity (12.9 mmol g-1 h-1, 96.5% selectivity), demonstrating its potential for industrial applications. Mechanistic investigations reveal a synergistic donor-acceptor interaction wherein the interlayer Ni sites modulate the electronic structure of the intralayer Co active centers, thereby optimizing the d-band center and facilitating the formation of the critical *COOH intermediate. This study establishes a powerful atom programming strategy for bimetallic sites within crystalline materials, paving the way toward designing catalysts with spatially controlled, multi-atomic architectures for complex chemical transformations.

Facet-selective synthesis of cadmium sulfide photocatalysts for high-efficiency CO2 conversion.

Utilization of off-gas from biomethanol production for combined heat recovery and power generation using a Gamma-type Stirling engine assembled with a heat recovery unit

A dual-steam extraction strategy for molten salt heat storage system enabling thermo-electric decoupling in a 660 MW CHP plant

ABSTRACT Coal spontaneous combustion (CSC) not only leads to significant resource waste but also releases toxic and harmful gases such as CO, posing severe threats to the environment and human health. In actual mine production, complex mining conditions facilitate CO accumulation, while ventilation volume affects CO generation in working faces. This study investigated the influence of ventilation volume on CO generation patterns during coal low-temperature oxidation (LTO) through programmed temperature-rise experiments. Based on generation kinetics, the apparent activation energy characteristics of three LTO (slow oxidation stage, accelerated oxidation stage, violent oxidation stage) were clarified. Using in situ Fourier transform infrared spectroscopy (FTIR), variations in five major active groups during these three stages under different ventilation volumes were analyzed, revealing the dynamic distribution features of key active groups in coal samples. Finally, the structure-activity relationship between CO generation and critical active groups was established via principal component analysis (PCA). The findings indicate that the concentration, yield, and generation rate of CO gas during LTO of coal are positively correlated with ventilation volume. C = O and -OH are the key reactive functional groups governing CO generation, jointly dominating its production. Meanwhile, -COOH, C = C, -CH3, and -CH2- indirectly regulate the CO release process by modulating reaction pathways and activation energy changes. These discoveries reveal the structure-activity relationship between CO generation and key reactive functional groups during coal LTO, providing a theoretical foundation and practical guidance for CSC prevention and early warning.

For a modern large city, the decarbonization of heat supply is a key area that determines the level of energy efficiency, independence, and resilience. Decarbonization of district heating (DH) systems is a highly relevant issue for countries with well-developed DH infrastructure, most of which was built in the previous century and designed for the use of fossil fuels. These systems face simultaneous challenges: reducing heat consumption, replacing obsolete equipment, and substituting fossil fuels with renewable energy sources and waste energy resources. At the same time, the reliable supply of consumers with thermal energy must be ensured. Addressing such a complex and multifaceted task requires the development of a scientifically justified strategy. The pace of DH modernization and decarbonization differs significantly across countries. For Ukraine, which has a developed but outdated DH sector, decarbonization of this important energy infrastructure is being implemented based on European experience while taking into account national specifics. This study is devoted to methodological and techno-economic aspects of the decarbonization strategy for large, outdated DH systems, considering the current state of such systems in Ukraine. The research addresses the problem of heat supply decarbonization at the scale of a large city with approximately 200,000 inhabitants, characterized by a developed but obsolete DH system: inefficient gas-fired boilers, combined heat and power (CHP) plants, outdated solid waste management system and non-integrated heat networks. Three principal directions for urban DH decarbonization are examined: 1) Reduction of primary energy consumption through building retrofitting, energy demand management, and heat loss reduction in networks; 2) Replacement of fossil fuel-based heat generation with environmentally friendly energy sources; 3) Integration of district heating networks. Bibl. 20, Fig. 9, Tab. 8.

The transition toward a circular bioeconomy requires efficient conversion of biogenic wastes and biomass into renewable fuels. This study explores the gasification potential of wastewater sludge (WWS) and food waste (FW), representing high moisture-content biowastes, compared with softwood (SW), a lignocellulosic biomass reference. An Aspen Plus equilibrium model incorporating the drying stage was developed to evaluate the performance of air and steam gasification. The effects of temperature (400–1200 °C), equivalence ratio (ER = 0.1–1), and steam-to-biomass ratio (S/B = 0.1–1) on gas composition and energy efficiency (EE) were examined. Increasing temperature enhanced H2 and CO generation but reduced CH4, resulting in a maximum EE at intermediate temperatures, after which it declined due to the lower heating value of the gases. Although EE followed the order SW > FW > WWS, both biowastes maintained robust efficiencies (60–80%) despite high drying energy requirements. Steam gasification increased H2 content up to 53% (WWS), 54% (FW), and 51% (SW) near S/B = 0.5–0.6, while air gasification achieved 23–27% H2 and 70–80% EE at ER ≈ 0.1–0.2. The results confirm that wet bio-wastes such as WWS and FW can achieve performance comparable to lignocellulosic biomass, highlighting their suitability as sustainable feedstocks for waste-to-syngas conversion and supporting bioenergy integration into waste management systems.

ABSTRACT Dual‐atom catalysts (DACs) provide great potential for boosted photoreduction of diluted CO 2 , while the significance of inert sites in DACs is still overlooked. Herein, by loading extra Zn atoms into conducive metal‐organic frameworks (CMOFs), we elaborately construct a well‐defined DACs with a NiZn─O 4 configuration to decipher the critical role of inert Zn sites in DACs. Under visible light irradiation in pure CO 2 , the NiZn─O 4 DACs with the optimal Zn/Ni ratio exert a boosted CO generation rate of 20.17 µmol h −1 with a selectivity of 97%, which is significantly higher than that of the pristine Ni─O 4 single atom catalysts (SACs) and most documented systems. Additionally, in diluted CO 2 , the activity difference between them increases, and the CO selectivity of Ni─O 4 SACs drops from 95% to 88%, while it remains nearly constant (94%) in the NiZn─O 4 DAC‐based system. Experiments combined with theoretical analysis demonstrate that the inert Zn sites enhance the electronic density of the coupled Ni sites, which accelerates electron transfer, promotes reduction kinetics, and lowers the energy barrier for the generation of * COOH key intermediate. This work highlights the intrinsic role of inert sites, paving new avenues for designing effective DACs for various applications.

Indonesia has set a target to achieve Net Zero Emissions (NZE) by 2060 and a 52% renewable energy share by 2030. Geothermal energy, with 29.5 GW potential, is critical, yet environmental performance of technologies remains poorly characterized, hindering sustainable decisions. This systematic review analyzes life cycle assessment (LCA) studies on binary, flash, and dry steam geothermal technologies. Scopus and Google Scholar searches using keywords "geothermal power plant" and "life cycle assessment" yielded 30 studies (2013–2025). Environmental burdens vary by technology, geology, design, and operations. Binary systems face high impacts from drilling, steel construction, and working-fluid leakage (up to 64% of global warming potential). Flash systems show major CO? and H?S emissions, reducible by 78% via abatement or hybrid flash-binary setups. Dry steam plants are dominated by non-condensable gas (NCG) emissions unless hybridized with Enhanced Geothermal Systems (EGS) or Combined Heat and Power (CHP), shifting hotspots to construction. Findings offer Indonesia actionable insights: select cleaner configurations, optimize drilling, deploy emission controls, and prioritize low-global-warming-potential fluids. This synthesis of site-specific LCAs creates a framework identifying hotspots and pathways, supporting evidence-based policies for sustainable geothermal expansion in Indonesia's energy transition.

With the continuous increase in the proportion of renewable energy in the power grid, enhanced operational flexibility of the power system is required. As baseload generators, combined heat and power (CHP) units are prime candidates for flexibility retrofits that guarantee grid stability. Among the available options, molten-salt thermal energy storage (TES) offers an energetically efficient route to decouple heat and electricity production in CHP plants. In this study, a 660 MW ultra-supercritical coal-fired unit is taken as the object of investigation. Sixteen technical routes incorporating steam extraction and electric heating for thermal energy storage and discharging are systematically designed. Results demonstrate that all the combined schemes significantly improve the operational flexibility of the unit. Among them, the C1-S1 configuration exhibits the most outstanding overall economic performance, with a six-hour thermal storage capacity of 294.34 MWh. The system exergy destruction is measured at 6258 kW, while the round-trip efficiency and thermal efficiency are determined to be 81.11% and 45.48%, respectively.

Electrochemical CO2 reduction is traditionally thought to require catalytic surfaces to overcome the high activation barrier of inert CO2 molecules. Here, we demonstrate that in bicarbonate solutions, hydrated electrons (e-aq) generated at the CO2 microbubble interfaces can activate CO2 independently of catalysts or applied bias. Using spin-trapping mass spectrometry, we directly observe CO2•- radical intermediates (CO2 + e-aq → CO2•-), while inert Pt electrode experiments confirm subsequent solution-phase CO generation (CO2•- + H+/•H → CO + H2O). Unexpectedly, in situ Raman spectroscopy reveals CO adsorption and C-H bond formation on Cu even at 0.6 VRHE, approximately 2.0 V above the reported potential for CO2 activation. The applied reduction potential (0-0.6 VRHE, above the onset of the H+/H2 reduction potential) modulates the interfacial e-aq/•H concentration through oxidative radical scavenging, enabling solution-mediated hydrogenation. These findings establish an unprecedented model in which electrolyte-driven processes operate in parallel with conventional surface electrocatalysis, challenging long-standing assumptions about the necessity of catalytic surfaces for CO2 activation.

ABSTRACT Selective CO 2 photoreduction via artificial photocatalysis into high‐value chemical feedstocks such as CO is a productive strategy for remitting environmental problems and energy crises. Nevertheless, photocatalysts generally endure low activity and poor product selectivity due to the low light/CO 2 capture and slow dynamic transfer of photogenerated electrons. Herein, we describe an all‐in‐one lignin‐based artificial thylakoid nanovesicle (AiO‐L‐ATN) using the confined growth strategy of lignin molecules, inspired by the chloroplast's photosynthesis mechanism. Such AiO‐L‐ATN possesses a high CO generation rate of 98.8 μmol g −1 h −1 at normalized active mass with a satisfactory selectivity of 92.1% in a gas‐solid system with H 2 O, exceeding 26 times that of the primary ZnCdS. Besides, introducing carbon nanovesicles significantly improves CO 2 capture performance, narrows the band gap, expands the wavelength range of light absorption, and accelerates the separation of photogenerated electrons. Density functional theory (DFT) calculation reveals that the carbon nanovesicles with various functional groups favor *CO 2 adsorption, *COOH production and conversion, as well as accelerate the dynamic transfer of photogenerated electrons, thereby endowing the outstanding CO 2 reduction rate and CO selectivity of AiO‐L‐ATN. This study not only provides valuable insights into the preparation of highly efficient photocatalysts but also offers novel avenues for CO 2 photoreduction.

ABSTRACT To address the limitations of conventional thermoresponsive hydrogels in sealing deep high-temperature goafs due to insufficient expansion, a novel expanding thermoresponsive hydrogel was developed using hydroxypropyl methylcellulose (HPMC) and chitosan (CS) as the matrix, glycerol (Gly) as a humectant, and a composite expanding agent (CEA, consisting of expandable microspheres and sodium bicarbonate in a 1:1 ratio). Response surface methodology optimized the formulation to 5 wt% HPMC, 0.5 wt% CS, 0.5 wt% acetic acid, 10 wt% Gly, and 0.6 wt% CEA, yielding a hydrogel with a lower critical solution temperature (LCST) of 63°C, an expansion ratio of 1.05, and a viscosity of 8548 mPa·s after 12 h. Scanning Electron Microscopy (SEM) revealed a compact, wrinkled microstructure, with the dense network isolating coal from oxygen and wrinkles enhancing water absorption. TG – DTG analysis indicated staged inhibition: 30–140°C, moisture evaporation provided cooling; 140–328°C, glycerol volatilization and NaHCO3 decomposition released CO2 with 67.23% mass loss, producing endothermic and inerting effects; above 328°C, a carbonized barrier suppressed combustion. Phase-transition sealing tests showed that at 80°C the hydrogel extended the pressure zeroing time of coal samples to 24 s, 41% longer than the conventional hydrogel. Inhibition tests delayed CO generation to 160°C, with a maximum inhibition rate of 43.3% at 180°C, 25% higher than the conventional hydrogel. Fire-extinguishing tests confirmed rapid coal cooling from 800°C to below 90°C within 30 s without reignition. This hydrogel offers a promising strategy for controlling spontaneous combustion in deep high-temperature coal seams with significant implications for mine safety.

CO Release Characteristics and Generation Pathways during High-Temperature Oxidation of Coal under Forced Rapid Heating