TY - JOUR
T1 - Correction to Insight into the Catalytic Effects of Open Metal Sites in Metal-Organic Frameworks on Hydride Dehydrogenation via Nanoconfinement
AU - Wu, Yi Ju
AU - Wang, Cheng-Yu
N1 - Publisher Copyright:
© 2020 American Chemical Society. All rights reserved.
PY - 2020/2/3
Y1 - 2020/2/3
N2 - In our original paper,1 we probed the catalytic ability between the same metal−organic frameworks (MOFs) with and without active Cu sites on chemical hydride ammonia borane (AB). Among our discoveries, we reported that when the open metal sites were covered by coordinated solvent dimethylformamide (DMF), ammonia was generated from the AB MOF composite (AB@MOF). There were two possible explanations: (1) There was no active Cu to capture ammonia. (2) DMF destabilized AB and released ammonia in DMFcoordinated MOF. In the second case, AB spent products could be different, as MOF with DMF may break the bond between B and N easily, while MOF without DMF may keep the B−N bond. In order to confirm the mechanism, NMR was applied to clarify the products from AB. In both AB@MOFs, they showed almost identical spectra in solid-state and solution 11B NMR. It proved that the copper open metal site may serve as an ammonia scrubber. Although it does not demolish the argument, we found that solid-state 11B NMR in Figure 6A and Figure S5 in the Supporting Information should be shifted by 20 ppm due to the wrong standard used. In the Results and Discussion: Dehydrogenation of AB@MOFs section, the ending of the paragraph beginning with "As ammonia was only observed..." should be modified to "Chemical shifts at 6 and 20 ppm in the solid-state 11B NMR (Figure 6A) are assigned to tetracoordinated B species of BN4 and sp2 BH groups,2,3 which can also be observed in the solution 11B NMR (Figure 6B). The results indicate that both MOFs (regardless of copper active sites) generate the same byproducts. Boron with reduced hydrogenation after the dehydrogenation process can be seen, and there is no BH3 moiety due to coordinated DMF destabilization." With the consideration of the correct standard in the solidstate NMR, we start to have a shared peak of sp2 BH groups in both solid-state and solution 11B NMR spectra and one extra peak of B sp3 groups found in solid-state NMR. It is because tetrahydrofuran (THF) used in solution NMR can only dissolve polyborazylene (PB) and makes only sp2 BH groups observable, while solid-state NMR can see more. Hence, although the revision does not alter our final conclusion (since both solid and solution NMR spectra of MOFs with and without DMF are still the same, it indicates that copper active sites in MOF are capable of ammonia removal), for research integrity purpose, we report the minor revision to our original paper. ACKNOWLEDGMENTS This work was supported by the Ministry of Science and Technology, Taiwan (Award MOST 104-2218-E-009-031- MY3 and Award MOST 107-2221-E-009-014).
AB - In our original paper,1 we probed the catalytic ability between the same metal−organic frameworks (MOFs) with and without active Cu sites on chemical hydride ammonia borane (AB). Among our discoveries, we reported that when the open metal sites were covered by coordinated solvent dimethylformamide (DMF), ammonia was generated from the AB MOF composite (AB@MOF). There were two possible explanations: (1) There was no active Cu to capture ammonia. (2) DMF destabilized AB and released ammonia in DMFcoordinated MOF. In the second case, AB spent products could be different, as MOF with DMF may break the bond between B and N easily, while MOF without DMF may keep the B−N bond. In order to confirm the mechanism, NMR was applied to clarify the products from AB. In both AB@MOFs, they showed almost identical spectra in solid-state and solution 11B NMR. It proved that the copper open metal site may serve as an ammonia scrubber. Although it does not demolish the argument, we found that solid-state 11B NMR in Figure 6A and Figure S5 in the Supporting Information should be shifted by 20 ppm due to the wrong standard used. In the Results and Discussion: Dehydrogenation of AB@MOFs section, the ending of the paragraph beginning with "As ammonia was only observed..." should be modified to "Chemical shifts at 6 and 20 ppm in the solid-state 11B NMR (Figure 6A) are assigned to tetracoordinated B species of BN4 and sp2 BH groups,2,3 which can also be observed in the solution 11B NMR (Figure 6B). The results indicate that both MOFs (regardless of copper active sites) generate the same byproducts. Boron with reduced hydrogenation after the dehydrogenation process can be seen, and there is no BH3 moiety due to coordinated DMF destabilization." With the consideration of the correct standard in the solidstate NMR, we start to have a shared peak of sp2 BH groups in both solid-state and solution 11B NMR spectra and one extra peak of B sp3 groups found in solid-state NMR. It is because tetrahydrofuran (THF) used in solution NMR can only dissolve polyborazylene (PB) and makes only sp2 BH groups observable, while solid-state NMR can see more. Hence, although the revision does not alter our final conclusion (since both solid and solution NMR spectra of MOFs with and without DMF are still the same, it indicates that copper active sites in MOF are capable of ammonia removal), for research integrity purpose, we report the minor revision to our original paper. ACKNOWLEDGMENTS This work was supported by the Ministry of Science and Technology, Taiwan (Award MOST 104-2218-E-009-031- MY3 and Award MOST 107-2221-E-009-014).
UR - http://www.scopus.com/inward/record.url?scp=85078895358&partnerID=8YFLogxK
U2 - 10.1021/acssuschemeng.9b07653
DO - 10.1021/acssuschemeng.9b07653
M3 - Comment/debate
AN - SCOPUS:85078895358
SN - 2168-0485
VL - 8
SP - 2115
EP - 2116
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 4
ER -