The enhanced catalytic performance of the GUF-14 hns nanosheets in comparison to the bulk hxl material and its three-dimensional fcu topology counterpart inspired us to further examine the catalytic activity of the MONs in the hydrolysis of the nerve agent simulant dimethyl (4-nitrophenyl)phosphate (DMNP, Figure ). Other Zr MOFs / MONs with low connectivity clusters are known to exhibit exceptional activity for this reaction and related conversions. The hydrolysis reaction was carried out via the procedure reported by Farha and co-workers, with 31 P NMR spectroscopy used to assess conversion (SI, Section S8.3). The GUF-14 hns MONs were able to completely hydrolyse DMNP within 12 minutes (Figures and), with a t1/2 of ~6.5 NU-1000 and UiO-66, again indicative of the high accessibility of the coordinatively unsaturated Zr6 cluster. However, the t1/2 of the GUF-14 hns phase is higher than those reported for the Zr-BTB MON (t1/2 = 2.1 min) and the benchmark catalyst MOF-808(Zr) (t1/2 = <0.5 min), suggesting that further optimisation of structure or activation would be required to closely compete with sector-leading materials.