First, we study the effect of cluster size and Ge content on the structure and stability of phosphorene deposited clusters. Figure displays the putative GM structures of the monometallic Ptn (n = 4-8) and Pt8-mGem (m = 0-7) series, along with the Bader charges. The n = 4 series is given in Figure of the Supporting information (SI). For all sizes, pure Pt clusters have very planar geometries wetting the surface, an indicator of a strong MSI. Surprisingly, the most stable cluster structures of Pt4 and Pt5 are found to be dissociated in two, forming either two dimers or one dimer and one trimer, respectively. This outcome may be related to the armchair structure of phosphorene. A closer inspection reveals that the Pt atoms are arranged in linear clusters anchored in the space between two consecutive planes. These linear clusters are then connected by additional Pt atoms that act as bridging units. In the smallest sizes these bridging atoms are missing and hence the clusters are preferentially fragmented. We can hypothesize that a phosphorene support could have a strong beneficial impact in the sintering resistance of Pt, since it might help keep the catalyst dispersed.