Erratum: Selective earth-abundant system for CO2 reduction: Comparing photo-and electrocatalytic processes (ACS Catalysis (2019) 9:3 (2091−2100) DOI: 10.1021/acscatal.8b03548)

Abstract

Further investigation of our Mn/Cu system in photocatalytic reduction of CO2 revealed for experiments with lowest catalyst loading an error of the quantification limit for the hydrogen determination. Hence, it is necessary to correct some of the values provided in Tables 1 and 2. In addition, these tables are extended by two additional columns for TONH2 and selectivity. The quantification limits and the standard deviations are discussed below the tables. We apologize for these mistakes and thank Maximilian Marx for raising this point and Anja Kammer for additional analytical work. Due to corrections, some changes are also necessary in the paragraphs below Tables 1 and 2 as well in the conclusions: Best results (TONCO = 913 with a selectivity of 94% and a quantum yield (?) of 0.47%; the use of a higher catalyst loading results in ? = 9.1%; for details see the Supporting Information) were obtained using catalyst 1 with a loading of 0.01 ?mol in 10 mL of CH3CN/TEOA (5:1, v/v), a Cat/ CuPS ratio of 1/100, and 5 h of irradiation with monochromatic light at ? = 415 nm and a power output of 70 mW (Table 1, entry 6). The use of higher catalyst loadings resulted in lower overall activities but led to selectivities up to 99% (Table 1, entries 3 and 4). Applying the same conditions, the activity of catalyst 2 was drastically reduced (TONCO = 98; Table 1, entry 8). In contrast, only traces of CO were observed employing catalyst 3 (Table 1, entry 9). For the in situ generation of the CuPS 1.0 ?mol of [Cu(CH3CN)4]PF6, an equimolar amount of bathocuproine and a 3-fold excess of xantphos were used in order to avoid the formation of the less active homoleptic Cu(NN)2 complex [Rosas-Herna?ndez, A.; Steinlechner, C.; Junge, H.; Beller, M. Green Chem. 2017, 19, 2356?2360; Fischer, S.; Hollmann, D.; Tschierlei, S.; Karnahl, M.; Rockstroh, N.; Barsch, E.; Schwarzbach, P.; Luo, S.-P.; Junge, H.; Beller, M.; Lochbrunner, S.; Ludwig, R.; Bru?ckner, A. ACS Catal. 2014, 4, 1845?1849; Armaroli, N.; Accorsi, G.; Cardinali, F.; Listorti, A. Top. Curr. Chem. 2007, 280, 69? 115]. Under these conditions, no formate was detected. Upon substitution of the in situ formed CuPS by the molecularly defined [Cu(xantphos)(bathocuproine)]PF6, the Mn catalyst turnover numbers and the selectivity were diminished resulting in a TONCO of 429 with a selectivity of 84% (Table 2, entry 1). By performing a control experiment under Ar atmosphere, it was confirmed that neither formate nor H2 and only traces of CO are formed in the absence of CO2 (Table 2, entry 2). Correspondingly, almost no conversion was observed when the CuPS was omitted, or the reaction was performed in the dark (Table 2, entries 4 and 6). A control experiment without the catalyst led to formation of 0.08 ?mol of CO accompanied by <0.30 ?mol of H2. When acetonitrile (CH3CN) was replaced by N-methyl-2-pyrrolidone (NMP) mainly hydrogen evolution was observed (Table 2, entry 5). Further, the TON was drastically decreased using only TEOA or BIH as SD (Table 2, entries 7 and 8). Therefore, we conclude that every component is vital for this light-driven, proton-coupled CO2 reduction. Carbon isotope labeling experiments using 13CO2 were performed to ensure that the evolved CO originates from CO2 (confirmed by GC-MS analysis).