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[Display omitted] • An effective strategy has been established by doping Ce into Cu NPs to tune the electronic state of Cu. • It attains the faradaic efficiency of C 2 H 4 as high as 53% with a current density of 150 mA/cm2. • Such performance is about 2.8-fold increase when compared with Cu NPs. • The electronic structure regulation and defective sites facilitate highly efficient C 2 H 4 production from CO 2 electroreduction. Coupling another metal element tends to produce catalytic controls of high activity and selectivity. However, this action is still poorly explored to improve the selectivity of the electroreduction of CO 2 to C 2 H 4 with high energy density. Herein, Ce-doped Cu nanoparticles (Ce-Cu NPs) are synthesized by one-step co-reduction method and presented a preferable example that promotes selective transformation of CO 2 to C 2 H 4 in a flow-cell configuration. Thereinto, high faradaic efficiency (FE) of C 2 H 4 for Ce-Cu-2 NPs could reach 53% with the current density of 150 mA cm−2, which is 2.8 times higher than that of Cu NPs. The outstanding performance mainly stems from tailoring the doped-Ce content shrinks particle sizes and forms oxygen defects due to the electron effect of nearby Ce atoms, boosting local electronic re-distribution of Cu. Meanwhile, in-situ Raman spectroscopies evidenced that the doping of Ce can enhance Cu site to bond *CO, which were beneficial to C–C coupling and thus endowed the catalyst with the superior catalytic performance in CO 2 electroreduction toward C 2 H 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • The N-Li 2 CO 3 cathode prelithiation additive enriched with GBs was synthesized. • The Σ(0 0 1) GBs in the N-Li 2 CO 3 exhibit enhanced Li-ion and electronic conductivity. • The ∼100 % capacity utilization of the N-Li 2 CO 3 (724 mAh/g) is obtained. • The improved energy density and lifetime of the Si-based full cells are achieved. Due to high theoretical capacity, Si anodes have attracted tremendous attention. Nevertheless, huge volume change during cycling together with large lithium loss substantially hinders their large-scale application. Prelithiation has emerged as a highly attractive strategy to compensate for the loss of active lithium. Li 2 CO 3 , which is ambient stable and delivers more than 5 times the theoretical capacity of the existing cathode materials, serves as an excellent cathode prelithiation additive. However, the practical application of Li 2 CO 3 is limited by its sluggish charge transport and high critical decomposition potential. Herein, we report a facile route to fabircating nanosized Li 2 CO 3 (N-Li 2 CO 3) materials enriched with grain boundaries (GBs). First-principles investigations reveal that the Li-ion transport behavior is dependent on the concentration of GBs. The Σ(0 0 1) GB model exhibits higher Li-ion and electronic conductivities compared to those of the bulk counterpart. As a result, the ∼ 100 % capacity utilization of N-Li 2 CO 3 with a delithiation capacity of 724 mAh/g is obtained, which is much higher than that of commercial Li 2 CO 3 (115 mAh/g), greatly enhancing the reversible capacity, energy density and lifetime of the LiNi 0.5 Co 0.2 Mn 0.3 O 2 //Si-graphite full cell. These findings provide valuable understanding of the role of GBs and the correlation between microstructure engineering and performance optimization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanosheet MoS 2 exhibits high activity and excellent stability in RWGS reaction. • CO desorption is facilitated through electron transfer from Mo to O atoms. • Redox mechanism is involved in MoS 2 and MoS 2 /MoO 2. A nanosheet MoS 2 catalyst is prepared via the hydrothermal method and O incorporation by calcination strategy. The X-ray and BET characterizations show that the calcination results in a considerable increase in crystallinity and specific surface area (from 48.82 to 84.49 m2/g), leading to the efficient adsorption of CO 2. In situ DRIFTS spectra and DFT calculations reveal that redox mechanisms are involved in the RWGS reaction on MoS 2. CO desorption is facilitated by O incorporation through electron transfer from Mo to O atoms and the higher barriers of CO hydrogenation and dissociation. CH 4 formation is effectively suppressed by the edge sulfur vacancies through the weakened adsorption strength of CO. A remarkable CO 2 conversion (57 %) and high stability (>1000 h) are obtained at 600 °C. This performance is superior to those of traditional supported catalysts. This study reports a promising two-dimensional layered material for exploring excellent performance catalysts for the reverse water gas reaction. [ABSTRACT FROM AUTHOR]

C@Fe 2 C/TiO photocatalytic CO 2 realizes C–C coupling to produce C2 fuel mainly due to the formation of a Z-scheme heterojunction between Fe 2 C and TiO, which changes the electron transmission path, and the CO* generated by TiO induces the production of C2. [Display omitted] • A novel C@Fe 2 C/TiO ternary composite catalyst is prepared. • The catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4. • The catalyst could be excited by NIR lights. CO 2 conversion is of great industrial importance in reducing green-house effect and reusing carbon-resource. Most studies are focused on the thermocataltic CO 2 conversion, which usually performs over noble metal catalysts at high temperature and pressure. Recently, photocatalytic CO 2 conversion has caused increasing attention owing to the energy save, low-cost and clean reaction route. The key problem is to design photocatalysts high activity and strong durability. Here, we choose to prepare a novel C@Fe 2 C/TiO ternary composite catalyst by reducing organic compounds under an ammonia atmosphere. During CO 2 reduction reaction in aqueous solution, the catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4 (35.483 μmol g-1h−1). Even irradiating with near-infrared lights, the catalytic conversion still proceeds successfully, but the main-product turns to be CH 4 (18.315 μmol g-1h−1). Based on the chanracterizations and DFT calculation, the high activity could be attributed to the cooperation between the Fe 2 C catalyst toward C 2 H 4 and the TiO 2 photocatalyst. Specially, C@Fe 2 C/TiO could be excited by NIR lights owing to the narrow-energy band gap. More importantly, the photoelectrons could be easily separated from holes owing to the presence of the Z-scheme heterojunctions, leading to the enhanced photocatalytic activity. This work provides new insights to understand the CO 2 reduction reaction mechanism to develop photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phytic acid was served as the etchant and phosphorus source to fabricate Co 2 P/hollow porous carbon hybrids. • Nano-sized Co 2 P particles were anchored inside the hollow N-rich porous carbon nanoleaf. • Confinement effect of carbon framework inhibits the particle aggregation. • Hollow porous structure provides abundant highly accessible active sites. • The optimized Co 2 P-NC shows good catalytic performance for HER, OER and water splitting. Developing low-cost and robust bifunctional transition metal phosphide (TMPs)-based catalysts with controlled structures and compositions is very important for overall water splitting (OWS). Herein, we report a new hollow leaf-like Co 2 P/N-doped porous carbon (Co 2 P-NC) composite, using the Co-doped zeolitic imidazolate framework nanoleaf (Co-ZIF-L) coated with polydopamine (PDA) layer as precursor and phytic acid as etchant and phosphorus source. Due to the etching and coordination reaction between phytic acid and leaf-like Co-ZIF-L, the hollow structure is formed after an one-set pyrolysis process. Within this as-prepared TMP/carbon composite, Co 2 P nanoparticles are encapsulated and dispersed in two-dimensional (2D) hollow leaf-like N-doped porous carbon. Benefiting from structural and componential advantages, the Co 2 P-NC exhibits high catalytic activity and durability for both HER and OER as well as OWS in the alkaline medium. Unlike the traditional gas–solid reaction method for preparing TMPs, the present synthetic strategy is more safe and simple, which is very feasible for designing hollow TMPs/porous carbon composites. [ABSTRACT FROM AUTHOR]

Self-assembled catalyst has the excellent selectivity and activity at low concentrations of CO 2. [Display omitted] • The self-assembled catalyst of CC3/Pd is synthesized. • Catalyst has the excellent selectivity and activity at low concentrations of CO 2. • The size effect of Pd nanoparticles has been systematically studied. • The mechanism of catalyst photoreduction CO 2 to CH 4 is studied. Porous heterogeneous photocatalysts containing both CO 2 adsorption and catalytically active sites can be might beneficial to achieve photoreduction of low concentrations of CO 2 to methane. Here, we show a self-assembled catalyst by combining catalytically-active Pd nanoparticles and porous organic cages for the CO 2 -to-CH 4 photoreduction reaction in the presence a molecular photosensitizer and a sacrificial reagent. The Pd nanoparticles is vital for the high CH 4 selectivity (over 97%) for the CO 2 photoreduction reaction, but they suffer from the low catalytic activity. When these Pd nanoparticles are equipped with an underneath support of porous organic cages, it dramatically boosts the catalytic activity with a high production rate of 78.5 μmol g-1h−1, while the CH 4 selectivity is up to ∼ 98% (electron basis). Importantly, when the photoreduction is performed under low concentration of CO 2 (10% concentration), over 98% of CH 4 selectivity and nearly 50% of the catalytic activity for the Pd-based catalysts retains. [ABSTRACT FROM AUTHOR]

Task-specific Py-Zn@IPOP X with multiple active sites are developed and exhibit durable high-activity for cycloaddition of CO 2 to epoxides under additive-free conditions. [Display omitted] • Novel task-specific Py-Zn@IPOP X are constructed in green ionic liquid medium. • Py-Zn@IPOP I with multiple active sites can activate CO 2 and epoxide simultaneously. • Py-Zn@IPOP I realizes efficient CO 2 cycloaddition under additive-free conditions. • The developed catalyst is easily separated and exhibits durable high-activity. Based on the Schiff base reaction and post-modification strategy, novel nanocomposites of pyridine-zinc-based ionic porous organic polymers (Py-Zn@IPOP X , X = Br, I, Ac) were constructed and structurally characterized. Various Py-Zn@IPOP X were applied to the transformation of CO 2 and epoxides into cyclic carbonates, and their catalytic activities were studied and discussed in detail. The results showed that Py-Zn@IPOP I possesses Lewis acid-base bifunctional features, and also modified with superior nucleophilic active groups, which exerted an important synergistic effect on activation of CO 2 and epoxide, and ring-opening of epoxide. Under co-catalyst/solvent-free conditions, Py-Zn@IPOP I could afford 96 % PC yield and 99 % selectivity at 120 °C and 2.0 MPa CO 2 pressure for 6 h, and turnover frequency (TOF) was high to 230 h−1. Moreover, the reusability and versatility of the catalyst were examined, and the catalytic mechanism was speculated according to the obtained results. Compared with previously reported porous polymer catalysts, Py-Zn@IPOP I requires much greener and milder reaction conditions while avoids the use of a co-catalyst, displaying bright prospects for the design and synthesis of ionic porous organic polymers for CO 2 activation and utilization. [ABSTRACT FROM AUTHOR]

Heterogeneous Co@PTPOFs with multiple Lewis acid/basic sites are developed and show excellent activity for cycloaddition of CO 2 and epoxides. [Display omitted] • Novel M@PPOFs with multiple Lewis acid/basic active sites are prepared facilely. • The M@PPOFs exhibit high specific surface area and good structural stability. • The 1.0Co@PPOFs-mediated CO 2 coupling reaction can conduct under mild conditions. • The optimum catalyst shows excellent reusability and broad substrate scope. • An insight into the M@PPOFs-catalyzed cycloaddition mechanism is proposed. A series of metal-decorated porous organic frameworks (M@PTPOFs) with cross-linked pyridyl and triazinyl were fabricated through a two-step method. The structures of the PTPOFs and M@PTPOFs were systematically characterized. As heterogeneous catalysts with Lewis acid/basic sites, the M@PTPOFs were applied to catalyze the model cycloaddition of CO 2 and epoxides. The optimal catalytic system and reaction parameters were investigated in detail. It was found that 1.0Co@PTPOF-400-15 cooperating with tetrabutylammonium iodide (TBAI) achieved the best catalytic performance, with a 96% product yield and 99% selectivity under mild conditions of 60 °C and 2.0 MPa CO 2 for 5.0 h. Moreover, 1.0Co@PTPOF-400-15 could be easily recycled by centrifugation and reused multiple times with nearly unchanged catalytic activity. Finally, the product yield and reaction parameters were compared with those of reported heterogeneous catalysts, and the possible synergistic catalytic mechanism of 1.0Co@PTPOF-400–15/TBAI was proposed. The multiple Lewis acid/basic active sites, robust structure and excellent catalytic performance are useful for the development of other high-efficiency heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Robust ZPOFs with multiple active sites are facilely constructed and show remarkable CO 2 adsorption and conversion performance under mild/green conditions. [Display omitted] • Novel ZPOFs with multiple active sites are prepared via ionothermal polymerization. • The ZPOFs show exciting dual-functions for CO 2 adsorption and conversion. • The ZPOF-mediated CO 2 coupling reaction can proceed under mild/green conditions. • The present ZPOF is easily separated and shows good stability and reusability. • The optimum catalyst exhibits excellent broad substrate scope. Porous organic frameworks fabricated by well-defined monomeric compounds with different active sites have been regarded as the promising nano-materials for improving the efficiency of CO 2 capture and utilization. In this study, novel zwitterionic porous organic frameworks (ZPOFs) alternately connected by benzimidazole, triazine and imidazolium modules were prepared facilely via ZnCl 2 -catalyzed bi-component polymerization. The influences of different monomer concentration and polymerization temperature on structural properties of the ZPOFs were discussed in detail. It indicates that the ZPOFs present attractive structure characteristics of high specific surface area and hierarchical pore structure, and have abundant hydrogen bond donors, Lewis bases and nucleophilic groups, respectively. The ZPOFs as-obtained were applied to CO 2 adsorption and conversion into cyclic carbonate by coupling with epoxide. The experiment results showed that the ZPOFs could afford the highest CO 2 adsorption capacity of 2505 μmol/g at 273 K and 1.0 bar CO 2 pressure. The effects of ZPOFs structures and reactions conditions on the catalytic performance were investigated. Under the optimized conditions of 70 °C, 2.0 MPa CO 2 for 2.0 h, and cooperating with tetrabutylammonium iodide (TBAI) cocatalyst, the ZPOF-450–30 could efficiently and selectively catalyze the CO 2 /epoxides cycloaddition reaction to yield corresponding cyclic carbonates. Moreover, the ZPOF-450–30 catalyst could be simply separated with durable high stability and activity. Finally, we compared the catalytic behaviors with reported similar heterogeneous catalysts and proposed a feasible ZPOFs-catalyzed mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Representative studies about CdS-based nanomaterials for the photoreduction of CO 2 are illustrated. • The modification strategies of CdS-based photocatalysts as well as DFT calculation are highlighted. • Perspectives and challenges in this field of photoreduction of CO 2 by CdS-based nanomaterials are presented. Semiconductor-based CO 2 photoreduction for generating chemical energy has recently attracted special attention owing to its tremendous potential for solving increasingly grim energy crises and environmental concerns. Among them, Cadmium sulfide (CdS)-based nanomaterials have attracted enormous attention on account of the relatively narrow band gap for harvesting visible-light and well-suited band position for CO 2 photoreduction. Herein, the comprehensive review focus on the application and progress in CO 2 photoreduction over CdS-based photocatalysts. In this review, we begin with a detailed discussion of CdS materials in CO 2 photoreduction, including fundamental of CO 2 photoreduction as well as products selectivity. In particular, we will highlight the modification of CdS materials for efficient CO 2 photoreduction. And the utilization of density functional theory (DFT) in the study of CO 2 photoreduction over CdS-based photocatalysts is emphasized. Moreover, the remaining challenges to investigate and optimize the catalyzing ability of CdS-based catalysts are stated to indicate possible future development of CdS. [ABSTRACT FROM AUTHOR]

• Silica-PEI adsorbent has been evaluated on a 100 kg scale in 150 h continuous test. • Optimal gas velocity for adsorbent in a bubbling fluidized-bed reactor was 5.1 cm/s. • ≥90% CO 2 removal efficiency was achieved with ≥7.5% dynamic sorption capacity. • Working capacity decreased with an increase of CO 2 partial pressure in desorber. • CO 2 sorption performance of the adsorbents decreased as testing time increased. Polyethyleneimine (PEI)/silica adsorbents have been considered as a promising candidate for post-combustion CO 2 capture, but the limited process study has been performed on a pilot-scale unit. Herein we report the 150 h continuous test results using a 100 kg sample of silica-PEI on a fluidized bed continuous unit. The CO 2 removal efficiency and dynamic sorption capacity were evaluated continuously by changing a number of variables. For the sorption reactor, the changing variables were inlet H 2 O concentrations of 0–8.3 vol%, inlet CO 2 concentrations of 12.0–21.5 vol%, bed temperatures of 50–70 °C and the bed differential pressures of 176–370 mmH 2 O. For the desorption reactor operated at the bed temperature of 129–130 °C, inlet H 2 O concentrations of 8.0–13.5 vol%, inlet CO 2 concentrations of 14.6–81.2 vol% and bed differential pressures of 430–580 mmH 2 O were used. During continuous operation, CO 2 removal efficiencies of over 90% were achieved with dynamic sorption capacities of 7.5 wt%. Solid sample collected during continuous operation were analyzed by TGA and 13C NMR to identity the decrease of CO 2 adsorption capacity and the extent of thermo-oxidative side reactions. Slow oxidative degradation of the silica-PEI occurred because the transporting adsorbent was exposure to the non-humidified air in the solid transport system. [ABSTRACT FROM AUTHOR]