Hydrodeoxygenation of furfural to 2-methylfuran over Cu-Co confined by hollow carbon cage catalyst enhanced by optimized charge transfer and alloy structure.

Hydrodeoxygenation of furfural over non-noble metal catalyst is an effective route to synthesis 2-methylfuran, but the reaction is often hampered by the low activity and selectivity of the catalyst. Herein, a bimetallic catalyst with CuCo alloy encapsulated in a hollow nitrogen-doped carbon cages (CuCo/NC) are fabricated by using ZIF-67 as a sacrificial template, which exhibited superior catalytic performance and a full conversion of furfural with a 95.7 % selectivity towards 2-methylfuran was achieved at an under relatively mild reaction conditions (150 ℃, 1.5 MPa H2 and 4.0 h). The characterizations and density functional theory calculations clearly evidenced that the introduced Cu species acts as a switch to regulate the activity and selectivity of the catalyst via two aspects. On the one hand, the Cu species perturb the Co electronic structure leading to adsorption configuration of furfural change from flat to vertical on the catalyst surface, which successfully hindered the hydrogenation of furan ring, resulting high selectivity towards 2-methylfuran. On the other hand, the formed CuCo (111) sites promotes the dissociation of hydrogen, cleavage of the CO bond and reduces the diffusion barrier of hydrogen so as to advance the formation of 2-methylfuran. This work may provide a feasible strategy for the design of nanoalloy catalyst for the hydrodeoxygenation of biomass platforms to value-added chemicals.

Methanol-induced assembly and pyrolysis preparation of three-dimensional N-doped interconnected open carbon cages supported FeNb2O6 nanoparticles for boosting oxygen reduction reaction and Zn-air battery.

Three-dimensional (3D) hollow carbon is one of advanced nanomaterials widely applied in oxygen reduction reaction (ORR). Herein, iron niobate (FeNb2O6) nanoparticles supported on metal-organic frameworks (MOFs)-derived 3D N-doped interconnected open carbon cages (FeNb2O6/NICC) were prepared by methanol induced assembly and pyrolysis strategy. During the fabrication process, the evaporation of methanol promoted the assembly and cross linkage of ZIF-8, rather than individual particles. The assembled ZIF-8 particles worked as in-situ sacrificial templates, in turn forming hierarchically interconnected open carbon cages after high-temperature pyrolysis. The as-made FeNb2O6/NICC showed a positive onset potential of 1.09 V and a half-wave potential of 0.88 V for the ORR, outperforming commercial Pt/C under the identical conditions. Later on, the as-built Zn-air battery with the FeNb2O6/NICC presented a greater power density of 100.6 mW cm-2 and durable long-cycle stability by operating for 200 h. For preparing 3D hollow carbon materials, this synthesis does not require a tedious removal process of template, which is more convenient than traditional method with silica and polystyrene spheres as templates. This work affords an exceptional example of developing 3D N-doped interconnected hollow carbon composites for energy conversion and storage devices.

ZIF-67-derived N-doped double layer carbon cage as efficient catalyst for oxygen reduction reaction.

The slow kinetic of oxygen reduction reaction (ORR) hampers the practical application of energy conversion devices, such as fuel cells, metal-air batteries. Here, an efficient ORR electrocatalyst consists of Co, Ni co-decorated nitrogen-doped double shell hollow carbon cage (Ni-Co@NHC) was fabricated by pyrolyzing Ni-doped polydopamine wrapped ZIF-67. During the preparation, polydopamine served as a protective layer can effectively prevent the aggregation of Co and Ni nanoparticles during the pyrolysis process, and at the same time forming a carbon layer to grow a double layer carbon cage. This unique hollow structure endows the catalyst with a high specific surface area as well as more exposed active sites. Also benefited from the synergistic effect between Ni and Co nanoparticles, the Ni-Co@NHC catalyst leads to an outstanding ORR performance of half-wave potential (E1/2, 0.862 V), outperforms that of commercial Pt/C catalyst. Additionally, when Ni-Co@NHC was used in the cathode for the zinc-air battery, the cell exhibits high power density (108 mW cm-2) and high specific capacity (806 mAh g-1) at 20 mA cm-2outperforming Pt/C. This work offers a promising design strategy for the development of high-performance ORR electrocatalysts.

Atomic Dispersion and Surface Enrichment of Palladium in Nitrogen-Doped Porous Carbon Cages Lead to High-Performance Electrocatalytic Reduction of Oxygen.

Metal-nitrogen-carbon (MNC) nanocomposites have been hailed as promising and efficient electrocatalysts toward oxygen reduction reaction (ORR), due to the formation of MNx coordination moieties. However, MNC hybrids are mostly prepared by pyrolysis of organic precursors along with select metal salts, where part of the MNx sites are inevitably buried in the carbon matrix. This limited accessibility compromises the electrocatalytic performance. Herein, we describe a wet-impregnation procedure by facile thermal refluxing, whereby palladium is atomically dispersed and enriched onto the surface of hollow, nitrogen-doped carbon cages (HNC) forming Pd-N coordination bonds. The obtained Pd-HNC nanocomposites exhibit an ORR activity in alkaline media markedly higher than that of metallic Pd nanoparticles, and the best sample even outperforms commercial Pt/C and relevant Pd-based catalysts reported in the literature. The results suggest that atomic dispersion and surface enrichment of palladium in a carbon matrix may serve as an effective strategy in the fabrication of high-performance ORR electrocatalysts.

Mononuclear Clusterfullerene Single-Molecule Magnet Containing Strained Fused-Pentagons Stabilized by a Nearly Linear Metal Cyanide Cluster.

Fused-pentagons results in an increase of local steric strain according to the isolated pentagon rule (IPR), and for all reported non-IPR clusterfullerenes multiple (two or three) metals are required to stabilize the strained fused-pentagons, making it difficult to access the single-atom properties. Herein, we report the syntheses and isolations of novel non-IPR mononuclear clusterfullerenes MNC@C76 (M=Tb, Y), in which one pair of strained fused-pentagon is stabilized by a mononuclear cluster. The molecular structures of MNC@C76 (M=Tb, Y) were determined unambiguously by single-crystal X-ray diffraction, featuring a non-IPR C2v (19138)-C76 cage entrapping a nearly linear MNC cluster, which is remarkably different from the triangular MNC cluster within the reported analogous clusterfullerenes based on IPR-obeying C82 cages. The TbNC@C76 molecule is found to be a field-induced single-molecule magnet (SMM).

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage.

OBJECTIVE: The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. METHODS: A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. RESULTS: During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (≥7mm) (p=0.037) were significantly associated with subsidence. CONCLUSION: The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (≥7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage

OBJECTIVE: The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. METHODS: A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. RESULTS: During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (> or =7mm) (p=0.037) were significantly associated with subsidence. CONCLUSION: The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (> or =7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.

Anterior Cervical Interbody Fusion with the Carbon Composite Osta-Pek Frame Cage in Degenerative Cervical Diseases

OBJECTIVE: Different types of interbody fusion cages are available for use in the surgical treatment of degenerative cervical diseases. The purpose of this study is to assess the technical feasibility, clinical efficacy and radiological results of intervertebral fusion with a carbon composite Osta-Pek frame cage (Co-Ligne AG, Switzerland) following anterior cervical discectomy. METHODS: 41patients (25males and 16females) with minimum 6months follow-up were included in the study. Disc height, cervical lordotic angle, segmental angle, and fusion rate were assessed by lateral radiographs. In this retrospective analysis, clinical outcome was assessed as evaluated according to Odom's criteria. RESULTS: Fifty-four cages were implanted in 30 single-level, 9 two-level, and 2 three-level procedures. The mean disc height, cervical lordosis angle, segmental angle were 4.2+/-1.8mm, 23.5+/-7.2degrees, 2.3+/-3.3degrees pre-operatively and 5.3+/-2.1mm, 24.2+/-8.3degrees, 3.8+/-3.5degrees at 6months after the surgery. Six months after surgery, there was radiographic evidence of fusion in 92.7% (38/41) of the patients. According to Odom's criteria, 37 of 41 (90.2%) patients experienced good to excellent functional recovery. CONCLUSION: These clinical and radiological results suggest that the carbon composite Osta-Pek frame cages are safe and effective alternative to autologous bone graft after anterior cervical discectomy for treatment of degenerative cervical disease.

Results of One level Anterior Cervical Discectomy and Fusion in the Degenerative Cervical Spinal Disorder: Comparison of 3 Arthrodesis Techniques / 대한정형외과학회잡지

PURPOSE: This study was designed to compare the outcome of anterior cervical discectomy and fusion (ACDF) with autogenous bone graft, ACDF with plating, and ACDF with carbon cage and plating for the surgical treatment of single-level degenerative cervical spine disorder. MATERIALS AND METHODS: We analyzed 60 cases who received single level ACDF for the treatment of degenerative cervical disorder with at least one year follow-up. Group A consisted of 21 patients treated by ACDF and autogenous bone graft. Group B consisted of 20 patients treated by ACDF and plate fixation, and group C consisted of 19 patients treated by Carbon cage and plate fixation. We compared 3 groups in terms of fusion status, change in Cobb angle and disc height, and clinical results using Odom method. RESULTS: The change of Cobb angle was -3.8 degreesin group A, -0.62 degreesin group B and 0.6 degreesin group C (p=0.042). The decreased disc height was 2.8 mm in group A, 1.4 mm in group B and 0.4 mm in group C respectively (p=0.001). In group A, the clinical results were excellent in 3 cases, good in 16 cases and fair in 2 cases. In group B, 4 cases were excellent, 13 good and 3 fair. And in group C, 5 cases were excellent and 14 good. CONCLUSION: ACDF with carbon cage and plate fixation proved an excellent surgical alternative that provided initial stability, maintained disc height and lordotic angle, and was accompanied by low donor site morbidity and reduced operation time for the treatment of single level degenerative cervical spinal disorder.

Comparative Study of Laparoscopic L5-S1 Fusion versus Open Mini-Anterior Lumbar Interbody Fusion

OBJECTIVE: To investigate the effectiveness and safety of the laparoscopic L5-S1 fusion, its perioperative parameters and long-term outcome are compared with those of open anterior surgical approach. METHODS: Data of 54 consecutive patients who underwent anterior approach for L5-S1 fusion either by laparoscopic or open mini-anterior lumbar interbody fusion(ALIF) from 1997 to 1999 were analyzed. Among them, 47 cases were available with more than 2-years follow-up data. In all cases, carbon cage and autologous bone graft were used. RESULTS: Twenty five patients underwent a laparoscopic procedure and twenty two a open mini-ALIF. Three laparoscopic procedures were converted to open ones. For perioperative parameter, only the operative time was statistically different(p=0.001) while length of postoperative hospital stay and blood loss were not. The incidence of operative complication was three in laparoscopic group and two in open mini-ALIF group. After the follow-up of at least two years, the two groups showed no statistical difference in visual analog scale for pain, Oswestry disability index, and patient satisfaction index. The fusion rate was 91% in each group. CONCLUSION: The findings of this study suggest that laparoscopic ALIF has similar effectiveness and safety with open mini-ALIF. However, the advantage of laparoscopic approach as a minimally invasive surgery should be reconsidered because no objective additional benefit was found.

Histologically Confirmed Bone Formation in the Carbon Fiber Cage Implant

The authors report the first case of histologically confirmed bone formation in the carbon fiber cage implant which used in posterior lumbar interbody fusion. A case of degenerative lumbar disc desease was treated by posterior lumbar interbody fusion with carbon fiber cage implant and local bone from posterior decompression. One year after the operation the cage was migrated into the spinal canal and compressed dural sac and nerve root. The cage was removed and investigated by light microscope. The histologic examination revealed viable bony traveculae in the cage. This finding suggest autogenous bone in the cage has a biologic bone-growth function after interbody fusion.

Transthoracic Interbody Fusion with Carbon Cage for Thoracic Disc Herniation Which was Downward Migrated

The authors report a case of thoracic disc herniation at T11/12 level which was downward migrated, presenting with signs of progressive spinal cord compression. The lesion was diagnosed by MRI. The operation was done by transthoracic transpleural approach using surgical microscope and the rib was not resected due to floating ribs of T11, 12. A Carbon cage with cancellous bones were used for the graft at the partial corpectomy site. The result of operation was good.