A composition and associated method for chemical mechanical planarization (or other polishing) are described. The composition contains a boron surface-modified abrasive, a nitro-substituted sulfonic acid compound, a per-compound oxidizing agent, and water. The composition affords high removal rates for barrier layer materials in metal CMP processes. The composition is particularly useful in conjunction with the associated method for metal CMP applications (e.g., step 2 copper CMP processes).